Venezuelan Guayana Research Articles

Novelties in the Neotropical Genus Ouratea Aublet (Ochnaceae)

A new section of Ouratea, section Cadzcae Sastre, and eight new species of Ouratea from Venezuela and adjacent countries are described: O. pendulosepala Sastre (sect. Cardiocarpae), O. oligantha Steyermark ex Sastre (sect. Cardiocarpae), 0. apurensis Sastre (sect. Ouratea), 0. paratatei Sastre (sect. Ouratea), O. cidiana Sastre (sect. Ouratella), 0. guriensis Sastre (sect. Ouratella), O. pseudoguildingii Sastre (sect. Ouratella), and O. squamata Sastre (sect. Ouratella). During preparation of the Ochnaceae treatment for the Flora of the Venezuelan Guayana, approximately 20 undescribed species of Ouratea Aublet from southern Venezuela and adjacent areas have been found. In order to properly place these new species within the subgeneric classification, a brief review and update of the previous system (Sastre, 1988) is needed. In the previous classification, I recognized six sections: Kaieteurea (Dwyer) Sastre, Cardiocarpae (Engler) Sastre, Polyouratea (Tieghem) Sastre, Persistens Sastre, Ouratella (Tieghem) Sastre, and Ouratea, which is the type section of the genus (with O. guianensis Aublet as the type). The new system also has six sections, but section Persistens is now placed in synonymy of section Ouratea, and section Caducae is newly described below. Aublet's (1775) description of Ouratea guianensis was based on a flowering sheet (in BM), illustrated by plate no. 152, and all additional material of this species studied for my 1988 classification was either in flower or old fruit, making it impossible to assess the structure of the carpids (fruiting carpels) with precision. Recent study of herbarium specimens of 0. guianensis from CAY, MO, NY, and VEN clearly shows, however, that its carpids are similar to those of the species previously included in section Persistens. This necessitates the transfer of section Persistens into the type section, and the recognition of a new section to include species previously (and erroneously) thought to be closely related to O. guianensis, but whose fruit structure is now seen to be different. Ouratea sect. Caducae Sastre, sect. nov. TYPE: Ouratea longifolia (Lamarck) Engler in Mart., Fl. Bras. 12(2): 316. 1876. Ochna longifolia Lamarck, Encycl. Meth. 4: 511. 1798. Inflorescentia terminalis, flores 5 sepalis, 5 carpellis, fructus 5 sepalis caducis, 1-3 carpellis verticalibus. Inflorescence terminal, flowers with 5 sepals and 5 carpels, sepals caducous in fruit, fruiting carpels 1-3, vertical. KEY TO THE SECTIONS OF OURATEA 1. Flowers with 2-4 sepals united in 2-3 parts . 1. sect. Kaieteurea 1. Flowers with 5 distinct sepals 2 2(1). Fruits with the carpels borne horizontally . 2. sect. Cardiocarpae 2. Fruits with the carpels borne vertically ..... 3 3(2). Flowers with (5)6-10 carpels ..... 3. sect Polyouratea 3. Flowers always with 5 carpels 4 4(3). Fruits with persistent sepals ... 4. sect. Ouratea 4. Fruits without sepals 5 5(4). Inflorescences axillary, rarely terminal .... 5. sect. Ouratella 5. Inflorescences always terminal 6. sect. Caducae DESCRIPTION AND NOMENCLATURE OF THE SECTIONS 1. Ouratea Aublet sect. Kaieteurea (Dwyer) Sastre, Bull. Mus. Natl. Hist. Nat. 4O. ser. 10, sect. B Adansonia 1: 50. 1988. Kaieteurea Dwyer, Bull. Torrey Bot. Club 70: 50. 1943. TYPE: Ouratea gillyana (Dwyer) Sandwith & Maguire. Inflorescence terminal or axillary; flowers with 2-4 sepals united in 2-3 parts, and 5 (-7 in O. articulata Sastre) carpels; fruits with sepals caducous or persistent and the carpels vertical. 2. Ouratea Aublet sect. Cardiocarpae (Engler) Sastre, Bull. Mus. Natl. Hist. Nat. 4O. ser. 10, sect. B Adansonia 1: 55. 1988. Ouratea sect. Eugomphia (Planchon) Engler, ser. Cardiocarpae Engler in Mart., Fl. Bras. 12(2): 307. 1876. TYPE: Ouratea cardiosperma (DC.) Engler. NovoN 5: 193-200. 1995. This content downloaded from 157.55.39.106 on Mon, 25 Apr 2016 06:34:51 UTC All use subject to http://about.jstor.org/terms

Two New Species of Weinmannia (Cunoniaceae) from the Venezuelan Guayana

Two new species of Weinmannia (Cunoniaceae) from the highlands of southern Venezuela are described and illustrated. Weinmannia ilutepuiensis P. E. Berry & J. Bradford is a simpleleaved, serrate-margined species known only from IhI-tepui in Estado Bolivar, and Weinmannia corocoroensis J. Bradford & P. E. Berry is a pinnateleaved species with tiny, revolute-margined leaflets currently known only from Cerro Coro Coro in Estado Amazonas. While preparing the floristic treatment of Cunoniaceae for the Flora of the Venezuelan Guayana and as part of a broader study of neotropical Weinmannia by the second author, two distinctive new species of Weinmannia were found among the collections examined from the tepuis, or tabletop mountains, of southern Venezuela. Both species were collected from relatively poorly explored mountains, one from I1l-tepui in Estado Bolivar, and the other from Cerro Coro Coro in Estado Amazonas. These species are described and illustrated below. Weinmannia ilutepuiensis P. E. Berry & J. Bradford, sp. nov. TYPE: Venezuela. Estado Bolivar: I1h-tepui, lower plateau, with varied habitats, rocky, boggy, and short forest to 5 m tall, 05025'03N, 60?29'W, 2500 m, 16 Apr. 1988, Liesner 23413 (holotype, MO; isotypes, NY, US, VEN). Figure 1A-D. Frutex vel arbor 1-5(10)-metralis, foliis simplicibus, laminis foliorum infra dense ochraceo-lanatis, ellipticis, coriaceis, marginibus serratis, 1.5-6.0 x 0.8-3.5 cm; pseudoracemis 4-6 cm longis, lanatis, pedicellis sub anthesi 1-2.5 mm longis post anthesin 2.5-4 mm longis; capsulis villoso-lanatis, 3-3.5 mm longis. Shrub or small tree 1-5(-10) m tall; young stems lanate, nodes hirsute. Leaves opposite, simple, elliptical, subcoriaceous, 1.5-6.0 cm long, 0.8-3.5 cm wide, broadly acute to rounded at the apex, broadly acute at the base, sparsely pilose to glabrescent and dark green on the upper surface, light brown and densely lanate-villous on the lower surface; secondary veins 10-15 per side, impressed on the upper surface and prominent on lower surface, subparallel from midvein until divaricating within ca. 4 mm of the margin with each branch joining an adjacent branch at a marginal sinus; margins serrate, planar to revolute, with 10-15 glandular teeth per side between successive sinuses or adjacent to a sinus; petioles 3-4 mm long, lanate; stipules broadly elliptical to suborbicular, 3-6 mm long, 3-5 mm wide, hirsute on the outside, dark brown and glabrous adaxially. Pseudoracemes in pairs at the branch apex, exceeding the leaves, 4-6 cm long, axis lanate. Flowers arranged in fascicles along the inflorescence axis with 1-several flowers per fascicle; bracteoles subtending fascicles, linear to obovate, 1.5-2 mm long, with long hairs on the dorsal surface; pedicels 1.0-2.5 mm long in flower, 2.5-4.0 mm long in fruit, lanate; sepals four, elliptic to narrowly deltoid, acute, 1-1.5 mm long, lanate abaxially, glabrous adaxially, persistent; petals four, narrowly obovate, 1.5-2.5 mm long, ca. 1 mm wide, glabrous, offwhite; filaments eight, 2.5-4.0 mm long, anthers oblong, ca. 0.4 mm wide, glabrous; ovary lanate, ca. 1.5 mm long, the 2 styles divergent and each 1.5 mm long, basally pubescent but glabrous toward the tips. Capsules 3.0-3.5 mm long (not including style), lanate-villous; seeds oblong, ca. 1.0 mm long, sparsely covered with simple hairs 0.5 mm long. Ecology and distribution. Occurring in patches of short forest on lower summit plateau overlying sandstone, known only from I1l-tepui in the eastern tepui chain of Estado Bolivar, Venezuela, between 2500 and 2630 m elevation. In the size and shape of leaves, inflorescences, flowers, and fruits, Weinmannia ilutepuiensis most closely resembles the Andean W. rollottii Killip, especially variety testudineata (Cuatrecasas) Bernardi. Both species belong to series Dryadifoliae Bernardi (Bernardi, 1963). However, W. ilutepuiensis differs in its dense, lanate-villous indumentum, including the calyx and the capsule (which are glabrous in W. rollottii). On the same helicopter trip to Ili-tepui during which Ronald Liesner collected the type specimen, he also made three other collections of Weinmannia (numbers 23422, 23417, and 23366, all at MO). None of these additional collections fits easily into NovoN 5:125-127. 1995. This content downloaded from 157.55.39.136 on Thu, 19 May 2016 04:37:37 UTC All use subject to http://about.jstor.org/terms

A New Section and Two New Species of Tragia (Euphorbiaceae) from the Venezuelan Guayana and French Guiana

A New Section and Two New Species of Tragia (Euphorbiaceae) from the Venezuelan Guayana and French Guiana

Novelties in the Pleurothallidinae (Orchidaceae) for the Venezuelan Flora

Two new species, Pleurothallis phoenicoptera and P. steinbuchiae, are described. Pleurothallis delascioi is synonymized under P. kerrii. Several other members of the Pleurothallidinae are recorded for the first time for Venezuela. During the course of our studies on the Venezuelan orchid flora for several floristic projects, including the Flora of the Venezuelan Guayana, the following species, previously unrecorded within the country's boundaries, were detected. Lepanthes spelynx Luer & Escobar, Amer. Orchid Soc. Bull. 54: 586. 1985. Among several other Lepanthes species recently collected in Andean Venezuela, this taxon is a new record for Venezuela. Specimen examined. VENEZUELA. Merida: cloud forest at La Montania study area, ca. 0.5 km S of La Montana Teleferico Station, 2,450-2,650 m, 26 Sep. 1987, D. L. Kelly 9100 (K, VEN). Pleurothallis archidiaconi Ames, Sched. Orch. 9: 29. 1925. TYPE: Trinidad-Tobago. Trinidad: Verdant Valley, 11 Dec. 1924, Hombersley s.n. (holotype, AMES). Pleurothallis archidiaconi Ames is widespread in the northern Amazon Basin, the Guayana Highlands, the Coastal Range of Venezuela, TrinidadTobago, and along the lower elevations of the eastern Andean foothills in Venezuela at 50-1,300(-1,500) m. Although similar to many other species in the Macrophyllae-Fasciculatae, Pleurothallis archidiaconi is characterized by its shallowly cordate, NOVON 4: 86-93. 1994. apically acuminate leaf, a 3-nerved dorsal sepal, 57 mm long, subequal or somewhat narrower than the synsepal, relatively broad, oblong petals with serrate or denticulate margins and obtuse to acute apices. The labellum is broadly ovate to broadly ovate-oblong, convex above the middle, and the apex is obtuse to rounded. The margins of the labellum are microscopically erose. The corners at the base of the labellum are distinctly angled to either side of the concavity, which accommodates the column foot. In some populations, the margins of the labellum are somewhat incurved in the middle part making the labellar outline pandurate in natural shape. The flower color varies from dark red in the Venezuelan Guayana and Coastal Range to yellowbrown with darker brown or reddish nerves in most other populations, including the typical one from Trinidad; all color combinations may be present in some populations. The plants are average sized for the Macrophyllae-Fasciculatae. Although collected many times, especially in Venezuela, the species has frequently been misidentified. Forms of the species with incurved labellar margins have been collected in Surinam (photographed by Werkhoven, 1986: 181, as P. monocardia Reichenbach f.) and in some areas of the Venezuelan Guayana, from where it was misidentified as Pleurothallis stenocardium Schlechter by Foldats (1970: 418). Pleurothallis stenocardium is a species from higher elevations in the Guayana Highland tepuis with smaller flowers and different perianth segments. The Venezuelan material from the Coastal Range and the Andes has been identified by Dunsterville & Garay (1959: 337) and by Foldats (1970: 345) as Pleurothallis monocardia, a Colombian Andean species with differThis content downloaded from 207.46.13.11 on Mon, 17 Oct 2016 05:19:30 UTC All use subject to http://about.jstor.org/terms

New Species and Combinations of Catostemma and Pachira (Bombacaceae) from the Venezuelan Guayana

Julian A. Steyermark had completed an extensive study of the Bombacaceae of southern Venezuela, but died before he was able to complete a treatment for the Flora of the Venezuelan Guayana. This paper lays the final groundwork for publication of this treatment and includes two new species, Catostemma durifolius and Pachira yapacanae, and nineteen new combinations in Pachira, into which all Venezuelan Guayanan species of Pochota, Bombacopsis, and Rhodognaphalopsis are placed. CATOSTEMMA AND RELATIVES Catostemma Bentham is a small genus of 1014 species found in forests of northern Brazil, southern Venezuela, the Guianas, and Colombia (Steyermark, 1987; Paula, 1969). This genus and the closely related Aguiaria Ducke (1 species) and Scleronema Bentham (4-5 species) are placed in the tribe Catostemmatae of the Bombacaceae, based on their unifoliolate-compound leaves, few(l-4)-seeded fruits, and their largely free staminal filaments (Hutchinson, 1967). After reading a description of the palmately compound juvenile leaves of Catostemma commune Sandwith (Sandwith, 1931), Hutchinson surmised that the adult leaves of Catostemma were unifoliolate-compound. A more recently discovered species, Catostemma digitatum J. D. Shepherd & W. S. Alverson, retains palmately compound (i.e., polyfoliolate) leaves into adulthood (Shepherd & Alverson, 1981). In contrast, no palmately compound juvenile or adult individuals of Aguiaria and Scleronema are known, but Hutchinson concluded that both genera were unifoliolate because of the swollen distal pulvinus on each petiole, a morphological trait shared by all three genera. However, as fresh material of other genera of Bombacaceae has become available in recent years, it is clear that most neotropical taxa share this trait. Thus, a swollen distal pulvinus cannot be used as a synapomorphy for the Catostemmatae. Nevertheless, similarities of flower and pollen structure (cf. Nilsson & Robyns, 1986) probably indicate a close relationship among all three genera. Affinities to other Bombacaceae and Malvales are

Reproductive biology in a tropical shrubland of Venezuelan Guayana

AbstractPlant sexual systems were evaluated in a tropical shrubland community of Venezuelan Guayana. Of 89 plant species, 73.0% were hermaphrodite, 12.4% monoecious, 10.1 % submonoecious, and 4.5 % dioecious. Temporal variation of sexual expression showed that hermaphrodite species were mostly adichogamous and monoecious, submonoecious species dichogamous (protandrous andprotogynous). Herkogamy was an important mechanism promoting cross‐pollination. Of 38 hermaphrodite species, 39.5 % were herkogamous. Plant sexual systems were not associated with life form. Most species were pollinated mostly by large and medium‐size bees. Pollinator specificity and pollen load transportation, were higher for monoecious species than for hermaphrodite, submonoecious and dioecious ones. Both pollinator specificity and pollen transportation were not significantly different among representatives of the latter three sexual systems. Plant sexual systems were significantly associated with dispersal syndromes; dioecious species had bird‐dispersal syndromes, the other sexual systems mostly anemochory, epizoochory and endozoochory; but many hermaphrodites were anemochorous.

Reappraisal of Subtribe Vargasiellinae (Maxillarieae, Orchidaceae)

Subtribe Vargasiellinae, proposed by C. Schweinfurth in 1952, is here validated. It is placed in tribe Maxillarieae, rather than in the Malaxideae, as originally proposed by Schweinfurth, based on new findings on the pollinarium structure of Vargasiella peruviana C. Schweinfurth. Schweinfurth described Vargasiella in 1952 from two Peruvian specimens collected by C. Vargas. morphology of the inflorescence and pollinarium puzzled the author; the absence of complete pollinaria in the specimens he examined led him to believe Vargasiella was close to subtribe Liparideae (in Schlechter's old system, referred to tribe Malaxideae Lindley in Dressier, 1990: 217). However, based on leaf and flower characters, Schweinfurth (1952: 152) suggested subtribal status for Vargasiella, but failed to validly publish the taxon. Schweinfurth (1958: 219) described a second species from the Venezuelan Guayana; the flowers he had available did not have complete pollinaria. Vargasiella venezuelana was collected a second time by G. C. K. Dunsterville (Dunsterville & Garay, 1965: 326; Dunsterville & Dunsterville, 1982: 37), but this material and his subsequently published drawing (Dunsterville & Garay, 1965: 326-327; 1979: 1037) did not present critical details of the pollinarium. Dressier (1990: 249) suggested the placement of Vargasiella in subtribe Zygopetalinae: The Andean Vargasiella has been described as having naked pollinia, but the pollinia appear to be superposed, and I suspect that it is closer to this group (i.e., subtribe Zygopetalinae). However, examination of recently collected specimens of Vargasiella peruviana indicate the pollinarium has four plano-convex pollinia, a short stipe, and a hooked viscidium (Fig. 1). pollinia do not appear to be superposed and flattened as in Zygopetalum and other allied genera. These features, combined with the fact that the labellum does not have any ridges or keels, a diagnostic feature of subtribe Zygopetalinae, indicate that Vargasiella, although closely allied to the Zygopetalinae, merits subtribal status. Vargasiellinae C. Schweinfurth ex G. Romero & Carnevali, subtrib. nov. TYPE: Vargasiella C. Schweinfurth, Bot. Mus. Leafl. 15: 150. 1952. Herba epiphytica vel terrestris; caulis elongatus, sine pseudobulbis; folia disticha, plicata, articulata; inflorescentia laxe racemosa; labellum simplex, ecallosum; pollinarium viscidio unico, stipite unico, polliniis quatro, planoconvexis, non-superimpositis. authors would like to request live and/or pickled specimens of Vargasiella from orchid collectors and growers from Peru and Venezuela. This material is urgently needed to undertake further studies, particularly of cytology, growth habits, and the development of the inflorescence. We hope the examination of additional specimens will shed some light on the placement of this interesting genus within the Maxillarieae. Specimens examined. Vargasiella peruviana C. Schweinfurth. PERU. CUZCO: Prov. Paucartambo, Pillahuata, 3,400 m, epiphyte in rainforest, floral segments white lined with pink, 11 Dec. 1942, C. Vargas 3010 (AMES); Convenci6n Prov., hills of Pintobamba, in humus forest, 2,400 m, perianth white with pinkish lip, 3-4 Mar. 1943, C. Vargas 3288 (holotype, AMES). PASCO: Oxapampa Prov., Cordillera Yanachaga, road over shoulder of Cerro Pajonal to Villa Rica drainage, 12 km SE of Oxapampa, cloud forest, 2,300-2,500 m, 10035'S, 75020'W, Terrestrial 1 m; stem zig-zag; petioles grooved; bracts green with purple rim; two lower sepals purple outside, whitish inside; upper sepal white with purplish stripe down middle; petals white, lip and undulate margin maroon tongue; stem purple, 9 Oct. 1982, R. B. Foster & D. Smith 9094 (MO); same locality, 14 km E of main Oxapampa-Villa Rica road, lumber road at top of cordillera; stunted cloud forest, 2,450 m, 10?35'S, 75015'W, terrestrial, flower white, maroon outside and on lip, 2 Mar. 1982, A. Gentry & D. Smith 35984 (MO); border Provincias Oxapampa and Pasco, San Cotardo, in dwarf forest, rich in Ericaceae, bamboo and Blechnum, with sphagnum layer below, in swampy places, 2,700 m, terrestrial, flowers white with red, 7 Mar. 1986, H. van der Werf et al. 8508 (MO). NOVON 3: 79-80. 1993. This content downloaded from 157.55.39.163 on Fri, 18 Nov 2016 04:14:51 UTC All use subject to http://about.jstor.org/terms

Studies in Schefflera (Araliaceae), VI. New Species and Subordinate Taxa in the Venezuelan Guayana and Immediately Adjacent Areas

Studies in Schefflera (Araliaceae), VI. New Species and Subordinate Taxa in the Venezuelan Guayana and Immediately Adjacent Areas

Orchidaceae Dunstervillorum VI: New Pleurothallidinae from the Venezuelan Guayana

The following two taxa are proposed as new: Pleurothallis erebatensis and Trichosalpinx oxychilos. Both species are illustrated with plates by the late G. C. K. Dunsterville. Comments are provided on their relationships. During preparation of the treatment of the Orchidaceae for the Flora of the Venezuelan Guayana, we have detected the following undescribed taxa in the subtribe Pleurothallidinae. Pleurothallis erebatensis Carnevali & G. Romero, sp. nov. TYPE: Venezuela. Bolivar: Municipio Sucre, alrededores de Santa Maria de Erebato, 4'59'N, 64049'W, 360 m, feb. 1989, Elio Sanoja 2554 (holotype, PORT; isotypes, MO, VEN). Figure 1. Species haec P. aphtosae Lindley affinis, sed planta minore, ovario glabro, sepalis extus conspicue carinatis, minute papillosis non conspicue pubescentibus, intus glabrescentibus non verruculosis, dorsali base non atenuato, synsepalo versus apicem connatis, labello angustiore discrepat. Epiphytic herbs, caespitose to shortly creeping, erect to subpendent; rhizome covered with scarious sheaths. Stems (1.5-)3-8.5 cm long, terete, the basal /-/ clothed in a close-fitting tubular brown sheath. Leaves 5.5-9.5 cm long, (1-)1.3-1.8(-2) cm wide, fleshy-coriaceous when fresh, coriaceous when dry, erect on the stem, narrowly elliptic to oblanceolate, apex obtuse to acute, the midnerve sulcate, dorsally angled. Inflorescences 5-10 mm long, 1-5, successive or 2 or 3 simultaneously, erect or deflexed downward; peduncle very short and completely covered by a sheath at the base of the leaf; rachis completely covered by the floral bracts, 4NOVON 3: 18-21. 1993. 7-flowered; floral bracts ca. 2 mm long, fleshy, broadly cupuliform, apex acute, dorsally carinate. Flowers resupinate or not, dark brownish red, opening + simultaneously; pedicel 0.9-1.1 mm long, terete, ovary 1.2-1.5 mm long, glabrous, terete. Sepals thick-fleshy, 3-nerved, dorsally prominently carinate, finely papillose on both surfaces but more conspicuously so without, apices sharply mucronate; dorsal sepal 4.8-5 mm long, 1.8-2 mm wide, concave, oblong to elliptic-oblanceolate when flattened, acute, forming a hood over the column; lateral sepals connate for 5/6 of their length into a concave synsepal 4.9-5.1 mm long, when spread 4.3-4.4 mm wide, basally produced into a prominent mentum. Petals 2.4-2.6 mm long, 0.9-1.1 mm wide, thin but fleshy, 1-nerved, oblanceolate to obtrullate, obtuse, margins in the apical half finely and irregularly erose, glabrous. Labellum 3-3.2 mm long, 1-1.1 mm wide in natural shape, 1.5 mm wide when flattened, 3-nerved, concave, narrowly oblanceolate in natural shape, becoming oblong-elliptic to elliptic when spread, rounded to obtuse, fleshy, thicker at middle, basally with a pair of minute, retrorse lobules, anterior margin erose-laciniate; disk covered with pubescence of hairs in transverse lamellalike rows, coarser in the apical half; callus composed of 2 submarginal, parallel keels with erose dentate margins, located in the middle '/3 of the labellum. Column 1-1.3 mm long, straight or ? arcuate; margins prominently winged, apically 3-lobed, basally produced into a conspicuous foot 1-1.3 mm long. Fruits 0.9-1.3 mm long, obliquely ellipsoid. (Subg. Acianthera (Scheidweiler) Luer, sect. Brachystachyae Lindley.) Pleurothallis erebatensis resembles several others in section Brachystachyae, and it is difficult to This content downloaded from 207.46.13.122 on Thu, 19 May 2016 05:43:52 UTC All use subject to http://about.jstor.org/terms Volume 3, Number 1 1993 Carnevali & Romero New Pleurothallidinae from the Venezuelan Guayana

New Species of Hedyosmum (Chloranthaceae) from Northern South America

Four new species of Hedyosmum, all belonging to subgenus Tafalla sect. Microcarpa, are herein proposed. Hedyosmum uniflorum occurs in mid-elevation montane regions in central Ecuador and differs from its closest relative, H. bonplan- dianum, by its basally rounded, sometimes oblique leaves, flocculose midveins, slightly fimbriate stipular appendages, and long, linear, dissected stigmas. Hedyosmum narinoense, which inhabits the western slopes of the western cordillera in southern Colom- bia, also has single-flowered cymules but is unique among the solitary-flowered cymule species by hav- ing shorter pistillate inflorescences and scabrous, scurfy leaf sheaths. The remaining two new species, H. tepuiense and H. intermedium, are found in the Venezuelan Guayana. Hedyosmum tepuiense is rec- ognized as distinct from the broadly ranging H. racemosum by virtue of its long stipular appendages, verrucose leaf sheaths, floccose midveins, and longer inflorescences. Morphologically intermediate be- tween H. gentryi and H. neblinae, Hedyosmum intermedium is distinguished by its glabrous, elliptic leaves and 2-3-flowered purple-fruited cymules. tall; young stems quadrate; older stems terete, with tubular leaf bases persisting, ultimately disintegrat- ing and leaving circular scars; internodes 3-8 cm long. Leaves elliptic, 7.5-15.5 cm long, 3-6.5 cm broad, with long-acuminate tips 0.5-1 cm long, rounded, often oblique at base, at margins sharply serrate with teeth 3-4 mm distant, drying subcor- iaceous, smooth to slightly scabrous; midveins im- pressed above, raised beneath, with sparse floccose multibranched trichomes; larger lateral veins 6-9, 0.6-1.8 cm distant, arcuate, raised beneath, gla- brous or occasionally with sparse strigose to floc- culose hairs; free portion of petioles 0.6-1.4 cm long, glabrous except for occasional flocculose hairs running down midrib onto petiole; petiolar sheaths 1.3-1.8 cm long, 0.5-1 cm broad at apex, inflated, slightly flared at apex, with two strigose lines ex- tending down from the free portion of petioles, per- sistent but disintegrating with age, each distal margin with two slightly fimbriate, stipular appendages 1- 2 mm long, extending above free portion of petioles ca. 0.5 mm. Staminate inflorescences not seen. Pis- tillate inflorescences axillary or terminal, racemes or sparsely branched panicles, 3.5-8 cm long with 16-46 cymules; subtending bracts similar in size and shape to the leaves or more frequently smaller; cymules l(-3)-flowered, alternately or oppositely ar- ranged on the rachis, 3-10 mm distant, sessile or on short peduncles 1-3 mm long; subtending floral bracts enclosing one-fourth to three-quarters of flow- er, with acuminate tips 0.5-1 mm long, margin entire or with occasional strigose hairs. Pistillate flowers slightly trigonous, ca. 3 mm long, ca. 2 mm broad, with or without a small pore on each face of the ovary; perianth lobes small, deltoid; stigmas usu- ally highly dissected, linear, 2-3 mm long, papillose. Fruiting cymules green (?).

A New Species of Xylopia (Annonaceae) from Southern Venezuela

Xylopia plowmanii is newly described from plants from Estado Apure and Estado Amazonas, Venezuela. It most closely resembles a group of emarginate-leaved species that includes X. emarginata, X. spruceana, and X. venezuelana. During the preparation of the Annonaceae treatment for the upcoming Flora of the Venezuelan Guayana, the following new species of Xylopia was recognized and is described below. Xylopia plowmanii P. E. Berry & D. Johnson, sp. nov. TYPE: Venezuela. Amazonas: Tobogan de la Selva, along Rio Coromoto, 35 km S of Puerto Ayacucho, approximately 5?22'N, 67?33'W, T. Plowman & F. Gudnchez 13523 (holotype, MO; isotypes, F, NY, U). Figure 1. Species Xylopiae emarginatae Martius, X. spruceanae Bentham et X. venezuelanae R. E. Fries proxima, differt vero: caulibus juvenilibus sparse adpresseque puberulentibus deinde subglabratis, foliis latioribus atque elliptico-oblongis, pagina inferiore glabris, excepta costa adpresse strigosa, calyce glabro leviter lobato, 2 mm longo, 3.5-4.5 mm lato, petalis exterioribus 14.5-18 mm longis, dorso inconspicue adpresso-pubescentibus, petalis interioribus 14-20(-24) mm longis. Tree 12-16(-20) m tall. Leaf-bearing twigs 0.82.8 mm thick, brown to grayish brown, at first finely appressed-puberulent, later becoming glabrate, lenticellate. Blades of mature leaves 5-8 cm long, 23 cm wide, subcoriaceous, discolorous, oblong to elliptic-oblong, rounded and conspicuously emarginate at the apex, narrowed toward the base but angled sharply 2-4 mm from the petiole, making the base obliquely truncate, glabrous except for midrib, which is strigose abaxially with hairs 1-2 mm long; midrib impressed adaxially, raised abaxially; secondary veins faint, 7-9 per side, at 60-70? angle to midrib, slightly raised on both surfaces of the blade, anastomosing ca. 3 mm from the margin; petioles 3-4 mm long, 1.1-1.3 mm wide, terete, shallowly canaliculate and pubescent adaxially, glabrous abaxially. Flowers axillary, commonly two (sometimes three) per axil; inflorescence axis below articulation with pedicel 1-2.2 mm long, 1.1-1.3 mm thick; pedicel 2.8-4 mm long, 0.7-0.8 mm thick at midpoint, with an amplexicaul bract attached 1.2-1.5 mm above the articulation; bract 0.9-1 mm long, 1-1.3 mm wide, quadrate to semicircular. Calyx cuplike, 3.5-4.5 mm diam., divided to about the midpoint into broadly triangular lobes 1.5-2 mm long, glabrous. Petals pale yellow adaxially, orange except for the yellowish base abaxially; outer petals 14.5-18 mm long at maturity, 2 mm wide at midpoint, strap-shaped, widening to 3 mm at base, base concave, apex obtuse, densely puberulent adaxially, very sparsely appressed-puberulent abaxially; inner petals subequal in length to outer ones and similar in shape or exceptionally to 24 mm long, 1.2 mm wide at midpoint, 2 mm wide at base, puberulent along the midvein adaxially, uniformly puberulent abaxially. Stamens numerous, 1-1.4 mm long, 0.20.4 mm wide, the outermost ones converted into staminodes 0.9-1.2 mm long, 0.4-0.5 mm wide; connectives dome-shaped, short conic or truncate, papillate; filaments 0.4 mm long. Carpels 6-10, l near; ovaries 0.9-1 mm long, pubescent; style/stigma 4.2-4.8 mm long, linear, with a few sparse hairs along edges; ovules 4 in a single row. Torus in flower 2.1 mm diam., the stamens leaving raised scars on the torus surface, the center of the torus excavated, with the ovaries concealed within the cavity with only the styles exserted. Pedicel in fruit 10 mm long, 2 mm wide, glabrate. Monocarps 4-6, stipitate, the seed-containing portion 1.9-2.8 cm long, 1-1.8 cm wide, irregularly ovoid, densely covered by a matted, ferruginous indument, turning brown and glabrescent at maturity; stipes 4-7 mm long, 1.5-2 mm wide. Seeds usually 3 per monocarp, at 60? angle to long axis of monocarp, 6.57.5 mm long, 4-5 mm wide, ellipsoid, smooth; aril bilobed. Distribution. Southern Estado Apure and northwestern Estado (formerly Territorio Federal) AmaNOVON 3: 99-101. 1993. This content downloaded from 207.46.13.75 on Sat, 03 Sep 2016 04:39:39 UTC All use subject to http://about.jstor.org/terms

New or Noteworthy Orchids for the Venezuelan Flora IX: New Taxa, New Records, and Nomenclatural Changes, Mainly from the Guayana Shield and Northern Amazonas

Research on the Orchidaceae of the Venezuelan Guayana and neighboring areas has yielded several novelties, new records, and nomenclatural changes. Nine species (one Dichaea, two Lepanthes, one Maxillaria, three Pleurothallis, one Sarcoglottis, and one Uleiorchis), a natural hybrid in Maxillaria, and two subspecies (one Myoxanthus and one Stelis) are newly described. New synonymies are proposed in Campylocentrum, Habenaria, and Octomeria. In addition, several miscellaneous country records are reported. Fifteen of the taxa presented are illustrated. Continued studies related to the orchid treatment for Steyermark et al.'s Flora of the Venezuelan Guayana have yielded several novelties and nomenclatural changes for the orchid flora of the area and from other parts of the Neotropics. These novelties have resulted from the study of material received from several recent expeditions or from the study of critical material mainly at the Orchid Herbarium of Oakes Ames (AMES), the Herbario Nacional de Venezuela (VEN), and the Missouri Botanical Garden (MO). The taxa are arranged alphabetically by subfamilies, subtribes, and genera, following Dressier (1990). SUBFAMILY CYPRIPEDIOIDEAE Selenipedium steyermarkii Foldats, Bol. Soc. Venez. Ci. Nat. 21: 254, fig. 1. 1961. This species was recently collected for the first time outside Venezuela, extending its range into Guyana. Specimens examined. GUYANA. Potaro-Siparuni Region: summit of Mt. Kopinang, 5?00'N, 59?55'W, 1,700-1,800 m, 8 Apr. 1988, Hahn, Judziewicz & Gopaul 4392 (MO, US). SUBFAMILY EPIDENDROIDEAE SUBTRIBE ANGRAECINAE Campylocentrum hondurense Ames, Sched. Orchid. 5: 37. 1923. TYPE: Honduras. Lanc tilla Valley near Tela, 250 ft. altitude, 16 Mar. 1923, Ames II 210 (holotype, AMES). Figure 1. Campylocentrum steyermarkii Foldats, Act. Bot. Venez. 3: 316, f. 4. 1968, syn. nov. TYPE: Venezuela. Tachira: El Piiial, Rio Frio, 250-300 m, 27 Aug. 1966, Steyermark & Rabe 96715 (holotype, VEN). Campylocentrum steyermarkii was based on a specimen in young buds with not fully developed spurs; otherwise it is identical to the type of C. hondurense. We have seen living material collected close to the original locality that confirms this idea. Recently C. hondurense has been collected in the Amazon Basin in Venezuela and Peru; this is the first record of this species for Peru. The species is now known from Honduras, Belize, Venezuela, and Peru. It is apparently always cleistogamous. Specimens examined. PERU. Madre de Dios: Tambopata, Cuzco Amaz6nico, Lodge Camp site 1, Plot E, 200 m, 14 June 1989, Niunez et al. 11029 (MO). VENEZUELA. Territorio Federal Amazonas: Rio Mavaca, 1?59'N, 65?6'W, ca. 200 m, 23 Mar. 1988, Ramirez & Laskowski 246 (VEN).

New Species of Ruellia (Acanthaceae) from the Venezuelan Guayana

Recent expeditions in the Venezuelan Guayana have resulted in additional new taxa in the genus Ruellia (Acanthaceae). The following places these novelties on record for the convenience of other taxonomists prior to the publication of the Flora of the Venezuelan Guayana. Five new Venezuelan species of Ruellia, R. wurdackii, R. steyermarkii, R. delascioi, R. liesneri, and R. bolivarensis, are described, illustrated, and compared with their closest relatives. Ruellia L. is the second largest genus of Acanthaceae, with approximately 250 species of perennial herbs and shrubs with a pantropical distribution. The genus, named for Jean de la Ruelle (14741537), a French physician and herbalist, exhibits large and usually showy flowers borne either singly or in various inflorescence forms, which are either axillary or terminal or both. The funnelform or salverform corollas are either red, yellow, white, or purple (mauve) with a narrow tube and an often campanulate limb with five spreading lobes. The genus is characterized by the four didynamous stamens each with bilocular anthers, which are usually muticous at the base. The capsules are either oblong or clavate, with the dissepiment remaining attached to the capsule wall at maturity. Each capsule contains between 4 and 20 plano-compressed, suborbicular seeds. These are provided with a mucilaginous coat that exhibits, after moistening, tapered, short trichomes with walls marked internally by rings or spirals (Long, 1970). In an attempt to identify recent collections of Ruellia from the Venezuelan Guayana, I have found five undescribed species of the genus. Key to the Venezuelan Guayana Species of Ruellia 1a. Inflorescence paniculate, flowers borne on simple or dichotomously branched penduncles or flowers in clusters of 2-4 at the leaf axil. 2a. Flowers axillary, sessile, verticillate and clustered. 3a. Corolla narrowly infundibular, 25 mm long, white with violet veins; leaves petiolate, the blades ovate-oblong R. menthoides 3b. Corolla funnelform, 35-50 mm long, light pink to pale mauve or purple; leaves sessile to subsessile, the blades linear to narrowly lanceolate R. geminiflora var. angustifolia 2b. Flowers terminal and axillary, pedicellate, pedunculate, the peduncles 25-100 mm long. 4a. Flowers terminating conspicuously long peduncles, these 70-100 mm long. 5a. Corolla tube white, the limb 15 mm broad, the lobes obovate, ca. 6 mm long and wide; peduncles slender, curved .... 1. R. wurdackii 5b. Corolla tube scarlet or crimson, the limb 25-30 mm broad, the lobes oblong, 12 mm long, 5-6 mm wide; peduncles rather stout, erect-ascending R. macrophylla 4b. Flowers not terminating on conspicuously long peduncles, these 25-60 mm long (if peduncle is more than 40 mm long then inflorescence is a terminal panicle 60-130 mm long). 6a. Corolla yellow, greenish yellow, or pale green, the limb oblique. 7a. Corolla pale green, 30-33 mm long, the lobes revolute-twisted with age; calyx segments narrowly ovate, 14-17 mm long, winged on the angles; leaf blades elliptic to oblong, 713 cm long and 3.5-5 cm wide 2. R. steyermarkii 7b. Corolla pale yellow or greenish yellow, 35-60 mm long, the lobes spreading with age; calyx segments linear-lanceolate, 25-30 mm long, membranous; leaf blades ovate or oblong-ovate, 18-30 cm long and 8.5-12 cm wide. 8a. Corolla pale yellow, 50-60 mm long, 20 mm wide near the mouth; stamens exserted, not reflexed; leaf blades oblong-ovate, 26-30 cm long, 10.5-12 cm wide, narrowed at the base R. malaca 8b. Corolla greenish yellow, 35 mm long, 10 mm wide near the mouth; stamens exserted, reflexed; leaf blades ovate, 18-20 cm long, 8.5-9.3 cm wide, obtuse at the base 3 . R . delascioi 6b. Corolla mauve, the limb regular ......... . R. tuberosa lb. Inflorescence spicate or a 2-3-flowered terminal fascicle. NOVON 2: 139-148. 1992. This content downloaded from 157.55.39.173 on Thu, 19 May 2016 05:43:41 UTC All use subject to http://about.jstor.org/terms

Orchidaceae Dunstervillorum V: Two New Species and a New Combination in Epidendrum from the Venezuelan Guayana

Two new species and a new combination are required for the treatment of Epidendrum for the Flora of the Venezuelan Guayana. The new species are Epidendrum caurense and Epidendrum nuriense. Neolehmannia pabstii is transferred to Epidendrum, with the new name Epidendrum dichaeoides. All three species are illustrated with previously unpublished plates by the late G. C. K. Dunsterville. Comments on affinities and geography are provided for all species. Although several authors (Barros, 1982; Dunsterville & Garay, 1976; Garay, 1977; Pabst, 1978) assign subtribal rank to some groups of the subtribe Laeliinae (members of former subtribes Epidanthinae L. O. Williams, and Stenoglossinae Benth.) that display well-developed viscidia, most modern orchidologists (e.g., Dressier, 1984; Hagsater, 1985) agree that most members of Epidendrum sensu lato display variously developed viscidia and that the difference between the proposed subtribes Epidanthinae and Stenoglossinae, and the Laeliinae is one of degree. There is a consensus in including most members of the Epidanthinae and Stenoglossinae, genera such as Epidanthus L. O. Williams, Amblostoma Scheidw., Nanodes Lindley, Neolehmannia Kranzlin, Stenoglossum Kunth, and Kalopternix Garay & Dunsterv., in the genus Epidendrum itself. Each of these segregate genera is apparently closer to a different group within the genus Epidendrum, and not to the other members of the Epidanthinae or Stenoglossinae, rendering Dunsterville & Garay's (1976) circumscription of these subtribes artificial. Another genus included in the Stenoglossinae, Cladobium Lindley, containing the sole species C. violaceum Lindley, clearly belongs in the genus Scaphyglottis Poeppig & Endl. because of its vegetative and floral morphology. Scaphyglottis, although a member of the Laeliinae, is only distantly related to NOVON 2: 312-318. 1992. Epidendrum and the other former members of the Stenoglossinae. The broad circumscription of the genus Epidendrum followed in the Orchidaceae treatment for the Flora of the Venezuelan Guayana requires the inclusion of the new species Epidendrum caurense (belonging to the Amblostoma group) and the transfer of Neolehmannia pabstii P. Braga to Epidendrum. Epidendrum caurense Carnevali & G. Romero, sp. nov. TYPE: Venezuela. Bolivar: Rio Caura, in rainforest close to Las Pavas Falls, where Upper Rio Caura separates from the Lower, ca. 300 m, May 1976, collected originally by F. B. Stevens, Dunsterville & Dunsterville 1354 (holotype, AMES). Figure 1. Species haec Epidendro lanipes Lindley similis sed ramas inflorescentia laxioribus, pubescentia rachidis laxioribus, floribus minoribus pallide flavo-viridis, lobo centrali oblongo non pandurato vel cuneato, carina centrali brevioris discrepat. Epiphytic herb; rhizome shortly repent, with the pseudobulbs ? aggregate. Pseudobulbs 30-50 cm long, erect, homoblastic, slenderly fusiform, 3-8leaved in the upper half. Leaves 15-25 x 1.5-2 cm, linear-elliptic, acute, subtended by a tubular sheath, midnerve finely sulcate and sharply carinate, blades generally ascending when young, tending to droop when fully grown. Inflorescence terminal, 2530 cm long, an arcuate panicle with slender, somewhat divaricate, subdensely many-flowered branches; peduncle remotely sheathed, terete, glabrous; rachis with scattered, irregular, moniliform hairs; floral bract ca. 3 x 2 mm, glabrous, ovate, obtuse. Pedicellate ovary 7.5-8 mm long, densely covered with moniliform hairs. Flowers resupinate or not, light yellowish green, with widely spreading perianth This content downloaded from 157.55.39.104 on Mon, 20 Jun 2016 05:54:51 UTC All use subject to http://about.jstor.org/terms Volume 2, Number 4 1992 Carnevali & Romero Epidendrum from the Venezuelan Guayana Figure 1. Epidendrum caurense Carnevali & G. Romero. -A. Habit. -B. Upper portion of the inflorescence. -C. Flower, lateral view. -D. Floral segments, spread. -E. Floral bract. -F. Anther and pollinia. segments; sepals ca. 7 mm long, 3-nerved, apex sharply mucronate, dorsal ca. 1.9 mm wide, narrowly elliptic, acute, acuminate, laterals ca. 2.3 mm wide, obliquely elliptic-oblanceolate, acute; petals slightly shorter than the sepals, ca. 0.6 mm wide, linear-oblanceolate, obtuse, 1-nerved, set at variable angles to the column. Labellum fused to column throughout the length of the latter, the free portion ca. 4.5 x 5 mm, sharply 3-lobed; lateral lobes obliquely ovate, ca. 2.5 x ca. 2 mm; central lobe 313 This content downloaded from 157.55.39.104 on Mon, 20 Jun 2016 05:54:51 UTC All use subject to http://about.jstor.org/terms

Three New Species and a New Combination in the Asclepiadaceae from the Venezuelan Guayana

In preparation of the Asclepiadaceae treatment for the Flora of the Venezuela Guayana, one new species of Matelea, M. stergiosii, and two new species of Ditassa, D. ottohuberi and D. verticillata, are herein described. A new combination is also made in Ditassa, D. bolivarensis. Matelea stergiosii Morillo, sp. nov. TYPE: Venezuela. Estado Bolivar: moist forest on rocky slopes, near Campamento Auraima, Rio Paragua, 6022'30N, 63?33'30W, 330 m, MayJune 1987, Stergios 10450 (holotype, VEN; isotypes, MO, MY, NY, PORT). Figure 1. Species haec Matelea squiresii (Rusby) Morillo proxima, sed recedit: foliis late ovato-ellipticis vel obovatoellipticis, corolla 7.8-10 mm diametro, corollae lobis, 33.4 mm longis, 2.4-3.2 mm latis, intus breviter et dense puberulentis, gynostegio, 1.6-1.65 mm alto, 2.3-2.6 mm diametro (0.95-1.2 mm alto et 1.55-1.95 mm diametro in M. squiresii); antheris 1.4 mm latis; coronae segmentis basi 1.2-1.25 mm latis. Twining vine; stems with short and inconspicuous pubescence in two rows; leaves opposite; petioles 0.5-1.3 cm long, puberulent, blades broadly ovateelliptic to obovate-elliptic, 3-5.5 x 1.2-3.3 cm, apex usually ? abruptly acuminate, base obtuse to cuneate, glabrous except for a few hairs along the midvein above, 5 or 6 pairs of lateral veins, 4 nectaries at the base. Inflorescence subaxillary, 2or 3-flowered; peduncle 1-2 mm long, bracts ovate, 0.6-0.7 mm long, ciliate along the margins; pedicels 2-2.5 mm long, glabrous. Calyx lobes ovate-elliptic, 1.8-2 x 1.1-1.3 mm, with few short, curved hairs outside and short cilia along the margins, the apex narrowly obtuse. Corolla rotate, 7.8-10 mm diam., the lobes 3-3.4 x 2.4-3.2 mm, apparently green and brown, densely short-appressed or erect-puberulent inside, with few short, curved hairs along a medial line outside, the apex obtuse. Gynostegium shortly stipitate, 1.6-1.65 mm long (tall) and 2.32.6 mm diam.; anthers horizontal, 1.3-1.4 mm wide. Pollinia horizontal, irregularly and narrowly ovate-truncate, 0.45 x 0.3 mm, caudicles 0.20.25 mm long, corpusculum narrowly sagittate, 0.2 x 0.1-0.12 mm. Corona formed by 5 columnshaped segments, which are basally expanded, the NOVON 2: 30-32. 1992. basal part 1.2-1.25 mm wide, margin almost entire. Fruits unknown. This species belongs to a difficult complex with Matelea squiresii, which is known from southern Venezuela and the Guianas (also probably in Brazil) from lowland moist forests. Matelea stergiosii differs clearly in the somewhat wider leaf blades, much wider corolla, and gynostegium and inner face of the corolla lobes with denser pubescence. Ditassa ottohuberi Morillo, sp. nov. TYPE: Venezuela. Territorio Federal Amazonas: summit of Cerro Coro-Coro, NW headwaters of Rio Manapiare, NW section of Serrania de Yutaje, 5?46'N, 66?12'W, 2,200 m, Nov. 1987, Huber 12290 (holotype, VEN; isotypes, MO, MY, NY, RB, TFAV). Species nostra Ditassae acerifoliae Lasser et Maguire affinis, sed differt: corolla subcampanulata, 1.9-2 mm diametro, lobis 1.3-1.4 x 0.8-0.9 mm; gynostegio breviter tipitato 0.6-0.65 mm longo; antherae alis 0.260.32 mm longis, corona exteriori segmentis oblongis vel anguste triangulari-oblongis, 0.65-0.75 x 0.2 mm, corona interiori segmentis 0.2 mm longis. Erect suffruticose plant, 20-30 cm high; stems shortly branched, branches rugose, the lower part with conspicuous persistent petiole bases, internodes 0.5-1 mm long, minutely erect-puberulent. Leaves apparently disjunctly verticillate or subspirally arranged, erect, up to 8 per whorl; petioles 0.6-1.8 mm long, decurrent, glabrous; blades fleshy, ? linear, roundly triquetrous in cross section, 0.8-1 x 0.05-0.07 cm, the apex mucronate, the base gradually cuneate, the surface glabrous, veins and nectaries not evident. Inflorescences axillary or interpetiolar, cymose, 1-3-flowered; peduncles 0.6-1.6 mm long, glabrous, bracts and bracteoles narrowly ovate, 0.6-1 mm long, glabrous; pedicels 2.5-2.6 mm long, glabrous. Calyx lobes narrowly ovate, 1.11.5 x 0.45-0.55 mm, obtuse. Corolla subcampanu ate, 1.9-2 mm diam., the tube 0.5-0.6 mm long, glabrous, the lobes obliquely ovate, somewhat concave, suberect in anthesis, 1.3-1.4 x 0.8-0.9 mm, glabrous outside, puberulent-papillose inside, the apex narrowly obtuse. Gynostegium shortly stipitate, 0.6This content downloaded from 157.55.39.141 on Sun, 11 Dec 2016 04:52:49 UTC All use subject to http://about.jstor.org/terms Volume 2, Number 1 1992

Two New Species of Paspalum (Poaceae: Paniceae) from Venezuela and Colombia

Morphological characters support the description of two new species of Paspalum: P. atabapense, from Depto. Atabapo, Venezuela, in group Alterniflora; and P. tillettii, from Comisaria del Guainia, Colombia, and Territorio Federal Amazonas, Venezuela, in an unspecified taxonomic group but clearly related to P. schultesii Swallen. Preparatory to completing an account of the genus Paspalum for the Flora of the Venezuelan Guayana, two new species are described and illustrated. Paspalum L., with more than 350 species, is one of the largest genera of grasses. It is confined primarily to the New World, although a few species occur in Africa, Asia, and Oceania. Several species are pantropical or nearly so, and two weedy species have now become widely naturalized as weeds in the tropics. A few have been widely distributed as forage grasses and have subsequently become naturalized in new areas. The most useful taxonomic treatment of this genus remains the monograph of the North American species (including Mesoamerica) by Chase (1929). Paspalum atabapense Davidse & Zuloaga, sp. nov. TYPE: Venezuela. Amazonas: Depto. Atabapo, SE bank of the middle part of Caio Yagua at Cucurital de Yagua, 3036'N, 66?34'W, 120 m, 8 May 1979, G. Davidse, 0. Huber & S. S. Tillett 17414 (holotype, MO; isotypes, IAN, SI, US, VEN). Figure 1. Gramen perenne caespitosum; culmi 45-75 cm alti. Folia basalia; ligulae 0.5-1.2 mm longae, glabrae; laminae 6-18.5 cm x 0.3-0.4 mm, filiformes. Racemus 1, 39.5 cm longus; rhachis 0.4-0.5 mm lata, exalata vel interdum anguste alata basin versus. Spiculae 2.6-3.6 x 1.0-1.3 mm, ellipticae anguste, singulares, pubescentes; gluma inferna absens; gluma supera 0.3-0.7 mm spicula brevior. Flosculus superus 2.6-3.5 x 1.0-1.3 mm, stramineus. Antherae 1.5-1.9 mm longae. Caespitose, perennial herbs. Culms 45-75 cm long, erect, unbranched above the base, with 2-3 nodes above the base; internodes cylindric, glabrous; nodes dark, glabrous or pilose. Leaves basal. Sheaths striate, rounded, densely pilose toward the base with appressed, whitish hairs, to sparsely pilose toward the apex, the margins glabrous. Ligules 0.5-1.2 mm long, membranous, glabrous, erose. Blades 6-18.5 cm long, 0.3-0.4 mm wide, filiform, involute, the adaxial surface scabrous, prominently ridged, the abaxial surface glabrous, the apex permanently involute, somewhat pungent. Inflorescences terminal, long-exserted; peduncle 4-17 cm long, cylindric, glabrous; raceme 1, 3.0-9.5 cm long, slightly arching, densely pilose at its base; rachis 0.4-0.5 mm wide, puberulent to glabrous, concavo-convex, unwinged or sometimes with partially developed wings 0.1-0.2 mm wide near a portion of the base, terminating in a spikelet; pedicels 0.1-0.3 mm long, densely short-pilose. Spikelets 2.6-3.6 mm long, 1.0-1.3 mm wide, solitary, plano-convex, narrowly elliptic, pilose. Lower glume always absent. Upper glume 2.4-3.0 mm long, 0.3-0.7 mm shorter than the upper floret, acute, 3-nerved. Lower floret sterile. Lower lemma as long as the spikelet, 3-nerved, glabrous to puberulent in the middle portion, pilose toward the margins. Lower palea usually absent, rarely developed and then to 5/6 as long as the lower lemma. Upper floret 2.6-3.5 mm long, 1.0-1.3 mm wide, as long as the spikelet, bisexual, narrowly elliptic, stramineous, chartaceous, smooth, papillose, the papillae regularly distributed; lemma 3-nerved, short-pilose, with prickle hairs at the apex. Stamens 3; anthers 1.5-1.9 mm long, purple. Styles 2, separate; stigmas about as long as the styles, plumose. Caryopsis (1.2-)1.4-1.5 mm long, 0.9-1.0 mm wide, obovate in outline; hilum punctiform; embryo ca. 2/5 as long as the caryopsis. Paratypes. VENEZUELA. AMAZONAS: Depto. Atabapo, area between the W base of Cerro Yapacana and the headwaters of Caio Cotua, 3?38'N, 66?52'W, 6 May 1979, Davidse, Huber & Tillett 17251 (K, MO, SI, US, VEN); Depto. Atabapo, sabanas y bosques ribereios en los alrededores de Canarip6, en la margen izquierda (Sur) del bajo Rio Ventuari, a unos 20 km al E de la confluencia NOVON 2: 193-197. 1992. This content downloaded from 157.55.39.209 on Sat, 14 May 2016 04:53:24 UTC All use subject to http://about.jstor.org/terms

A New Species of Guadua, G. ciliata (Poaceae: Bambusoideae: Bambuseae), from Venezuela and Brazil

The genus Guadua, as recognized by Soderstrom & Londoiio (1987), comprises ca. 30 species and is restricted to lowland areas of the New World. It is included in subtribe Guaduinae of the tribe Bambuseae by Soderstrom & Ellis (1987). Species of Guadua are typically large, erect, woody bamboos with thorns. The type species of the genus, G. angustifolia Kunth, is the largest bamboo of the New World and among the largest in the world. McClure (1973) enumerated the species but recognized the group as Bambusa subg. Guadua (Kunth) Hackel. While writing an account of the genus for the Flora of the Venezuelan Guayana, it became apparent that a suite of collections from Venezuela and Brazil represents a new species in the genus.

Nomenclatural Changes and Range Extension in Leiothrix flavescens (Bong.) Ruhl. (Eriocaulaceae)

The Eriocaulaceae comprise about 1,200 species distributed throughout the tropical and subtropical regions of the world (Kral, 1989). The largest number of genera and species are found in high-altitude campos of South America, especially in the Brazilian Shield (Minas Gerais and Bahia) and the Guayana Shield in Venezuela. Most species are endemic to restricted localities, often found on only one mountain or tepui summit. However, some species, such as Leiothrix flavescens, Paepalanthus tortilis (Bong.) Koern., and Syngonanthus caulescens (Poiret) Ruhl., occur disjunctly in both Shield areas. A revision of the genus Leiothrix Ruhl., restricted exclusively to South America, is in process, with three new species recently published (Giulietti, 1988). A treatment of the genus for the Flora of Venezuelan Guayana is also being prepared by the junior author. Leiothrix flavescens is the species with the widest geographic distribution in the genus, including areas of Brazil, Venezuela, Peru, and Guyana. This fact, together with the considerable phenotypic variation, has led to the recognition of several taxa, many of which are here reduced to synonymy, and some of which are retained at the varietal level.

Six New Bamboos (Poaceae: Bambusoideae) from the Venezuelan Guayana

The grass flora of the Guayana Highlands is a rich one and includes many poorly known bamboos (Poaceae: Bambusoideae). Twenty-one genera and 75 species of bambusoid grasses are known from the region, including the following six species newly described for the Flora of the Venezuelan Guayana. Judging from the intriguing sterile but as yet unidentifiable bamboo collections that remain in herbaria, more novelties may be expected from this region in the future.

A New Combination in Tabernaemontana (Apocynaceae)

In preparation of the Stemmadenia and Tabernaemontana (Apocynaceae) treatments for the upcoming Flora of the Venezuelan Guayana, the following new combination is required.