Lower Palea Research Articles

TRIVALE, THE NEW WINTER WHEAT VARIETY ADAPTED TO THE LUVIC SOIL CONDITIONS

Improving wheat for increased adaptability to luvic sol conditions in the south of the country has made significant progress lately. The sufficiently wide genetic dowry available has shown that even in the conditions of white luvic soil in the south of the territory, varieties with tolerance to aluminum ions can be obtained. The Trivale variety obtained under these conditions proved new plant characteristics, including those required by the new intensification conditions. And in this case, some gains of morphological characters were found. Their study could be useful in the constant progress of wheat improvement. From the data obtained in the two years of experimentation it was found that the length of the straw was 69-76 cm, with the thickness at the base of 3.4-3.5 mm. The length of the spike was on average 8.7-9.0 cm, and its weight was between 2.1 g and 2.4 g. The spikelets in a spike were 18.4-18.8 in number. In the spikelet, the outer glume measured 8.7 mm, the lower palea 9.7-10.0 mm, and the awns measured an average of 5.8-6.4 cm. 41.2-42.7 grains were formed in a spike, with mean weighing of 1.7-1.8 g. The grains were 6.5-7.0 mm long, 3.1-3.2 mm thick, and the mass of one thousand grains was 39-43 g. Positive correlations were generally obtained between the morphological characters. The data obtained demonstrate a progress in improving the morphological characteristics of the Trivale variety, due to the gain of a tolerance to the concentration of aluminum ions into the soil.

Hymenachne panduranganii sp. nov. from Nilgiri Biosphere Reserve, India

Hymenachne panduranganii, a new species of Poaceae collected from a wetland area of Wayanad Wildlife Sanctuary in Kerala, which constitutes the core area of Nilgiri Biosphere Reserve (NBR), is described and illustrated. The new species differs from the related species H. assamica in having 1.0–1.5 m tall culms, 3.7–4.0 mm long spikelets, floret with a distinct lower palea and having only 2 stamens. To further enunciate the differences, an identification key to the Indian species of Hymenachne is provided.

A Peculiar Amphitropical Genus of Paniceae (Poaceae, Panicoideae)

Fil: Scataglini, Maria Amalia. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Instituto de Botanica Darwinion. Academia Nacional de Ciencias Exactas, Fisicas y Naturales. Instituto de Botanica Darwinion; Argentina

<I>Morronea</I>, A New Genus Segregated from <I>Panicum</I> (Paniceae, Poaceae) Based on Morphological and Molecular Data

Abstract Taxonomic features of species of Panicum section Parviglumia are reviewed and compared with those of other taxa in tribe Paniceae. The new genus Morronea, including six species ranging from Mexico to Argentina, is proposed on the basis of morphological and molecular characters. They are plants growing at forest edges, with membranous-ciliate ligules, lower glume reduced, 1/6 to 1/4 the spikelet length, lower palea and lower flower absent, and upper anthecium indurate with simple papillae and conspicuous macrohairs all over its surface. The new combinations: Morronea arundinariae, M. cayoensis, M. guatemalensis, M. incumbens, M. parviglumis , and M. trichidiachnis are proposed and the new genus is compared with other genera of the tribe Paniceae.

<I>Mayariochloa</I>, a New Monotypic Genus Segregated from <I>Scutachne</I> (Poaceae, Panicoideae, Paniceae)

Abstract The genus Scutachne (Poaceae, Paniceae) is revised. This American genus, which included two species from the Caribbean, was circumscribed on the basis of morphological and molecular characters. To analyze both species of the genus, S. amphistemon and S. dura, a detailed study of the micromorphology of the upper anthecium and leaf anatomy, together with exomorphological characters, was performed. Both species differ in vegetative and reproductive characters, including blade distribution, ligules, presence of axillary inflorescences, consistency of upper glume, lower lemma, and lower palea, presence of a lower flower, upper anthecium ornamentation, and presence of a rachilla extension. Anatomically, S. dura is a C4 PCK species, while S. amphistemon is a C3, non-Kranz taxon. The molecular phylogenetic analysis supports these morphological differences. As a result, we concluded that Scutachne, as presently circumscribed, is a polyphyletic genus. Therefore, the genus is here redefined and S. amphistem...

Digitaria killeenii (Poaceae: Panicoideae: Paniceae), a New Species from Bolivia

Abstract Digitaria killeenii A. S. Vega et Rugolo, a new species from Bolivia, is described and illustrated. Additional micromorphological characters in the spikelets are also described. The presence of an apical, abaxial pair of stomata on the upper lemma and the presence of occasional brownish hairs on the lower palea constitute the first report in the genus Digitaria. The taxonomic position of D. killeenii is discussed and its inclusion in section Clavipilae (Stapf) Henrard is proposed. A comparative table and some remarks about the related taxa are included. Communicating Editor: Fred Barrie

Setaria carinata (Poaceae, Paniceae): Especie Nueva de Venezuela

A new species from Venezuela, Setaria carinata S. Nozawa & Pensiero, is described and illustrated. Setaria carinata differs from closely related species by the number of bristles (nine to 10 per spikelet), the ornamentation of the strongly carinate upper lemma, and its narrow lower palea. An identification key to discriminate between similar species is presented.

Parodiophyllochloa , a New Genus Segregated from Panicum (Paniceae, Poaceae) Based on Morphological and Molecular Data

Abstract Taxonomic features of species of Panicum, previously classified in section Cordovensia, subgenus Dichanthelium, of Panicum, are reviewed and compared with those of other taxa in the Paniceae. The new genus Parodiophyllochloa is proposed on the basis of ecological and morphological features (i.e. plants growing at the edge of forests, with membranous ligules, lower glume more than 1/2 the spikelet length, lower palea and lower flower absent, and upper anthecium indurate with simple papillae all over its surface) and chloroplast ndhF sequences to include six species ranging from Mexico to Argentina. The new combinations: Parodiophyllochloa cordovensis, P. missiona, P. ovulifera, P. pantricha, P. penicillata, and P. rhizogona are proposed. The new genus is compared with other genera of the Paniceae.

Morphological interpretation of the spikelet in Digitaria atra (Poaceae: Panicoideae: Paniceae) and emended generic description

Digitaria atra is illustrated for the first time and the original description is emended. The diagnosis of the genus Digitaria is completed by introducing modifications related to the spikelet's morphology and the lower lemma's consistency. Some remarks about the lower palea are included. The unusual morphological characteristics of the spikelet of D. atra are compared with the tribe Isachneae and some genera of Paniceae.

A New Species of Streptostachys (Poaceae: Paniceae) from Brazil

A new species of Streptostachys, S. rigidifolia, from the Brazilian state of Maranhao is described, illustrated, and compared with previously described species in the genus. Anatomical data on the leaf blade of the new species are also provided. Upon examination of recent gatherings of Poaceae from Maranhao, Brazil, a new species of Streptostachys P. Beauvois was encountered, which is here described, illustrated, and compared with species previously included in the genus by Morrone & Zuloaga (1991). Streptostachys rigidifolia Filgueiras, Morrone & Zuloaga, sp. nov. TYPE: Brazil. Maranhao: Loreto, BR-230, estrada para Sao Raimundo das Mangabeiras, ca. 22 km de Sao Raimundo, 6?56'S, 45?19'W, cerrado baixo cor estrato graminoso aberto, 13 maio 1988, L. B. Bianchetti, F. R. Ferreira & J. N. Silveira 634 (holotype, CEN; isotypes, B, BM, IBGE, K, MO, R, RB, SI, SP, UB, US). Figures 1-3. Ab omnibus speciebus generis flosculo superiore glabro papillis compositis ornato differt. Streptostachys ramosa similis sed plantis 68-95 cm altis, inflorescentia racemosa vel subpaniculata 6-17 cm longa abunde differt. Robust, stout, caespitose and short-rhizomatous perennial. Culms 68-95 cm tall, simple, bearing basal and cauline leaves; internodes cylindrical, hollow, glabrous; nodes swollen, shortly pilose with whitish hairs. Sheaths pilose, more so toward the base, or glabrous, striate, one margin hyaline, the other ciliate. Ligules a ciliate rim ca. 1 mm long, with hairs up to 7 mm long, behind the ligule at the base of the blade and on the upper margins of the sheaths. Blades lanceolate, 25-50 cm long, 5-8 mm wide, rigid, glabrous or with few scattered hairs, strongly striate, rounded at the base, the apex pungent, acuminate, the margins denticulate and/or ciliate. Peduncle cylindrical, scabrous, to 30 cm long. Inflorescence exserted, racemose or subpaniculate, 617 cm long, formed by 2-6 branches 9-11 cm long, all bearing unilateral spikelets along their entire length; main axis short, triquetrous, scabrous, terminating in a spikelet; spikelets solitary on the branches, the pedicels 1-3 mm long, swollen, partially adnate to the rachis of the branches. Spikelets narrowly ellipsoid, 5-8 mm long, shortly pilose, with thickened, conspicuous internodes between the glumes, and florets; upper glume and lower lemma subequal, conspicuously coriaceous. Lower glume ovate, 3-6 mm long, /,-2/ the length of the spikelet, acute, 3(-5)-nerved, adaxial, slightly asymmetrical. Lpper glume 5-6 mm long with a few short hairs throughout, 5-nerved, the nerves anastomosed toward the apex. Lower floret male; stamens 3, the anthers 3 mm long; lodicules 2, truncate, conduplicate, 0.5-0.8 mm long; lower lemma 5.5-6.5 mm long, 5-nerved, prominently pilose toward the apex; lower palea well developed, lanceolate, 4.2 mm long, 1.6 mm wide, hyaline, strongly 2-nerved. Upperfloret narrowly ovoid, 4.5 mm long, 1.6 mm wide, indurate, pale, shiny, with regular compound papillae evenly distributed over the surface of the lemma and palea; lemma 5-nerved; styles 2, free from the base of the gynoecium; stigmas plumose, purple; stamens 3, with purple anthers; lodicules 2, conduplicate, 0.5-0.8 mm long. Caryopsis planoconvex, 3-3.5 mm long; hilum linear along the entire length of the caryopsis. Streptostachys rigidifolia is known only from a single population in the municipality of Loreto, Maranhao, Brazil, in cerrado vegetation. This species has been included in Streptostachys because of its inflorescence type, the thickening of the rachilla between the glumes and florets, the nervation of the glumes and lower lemma, and the linear hilum (Morrone & Zuloaga, 1991). Streptostachys rigidifolia is unique in the genus because of its glabrous upper floret, with compound papillae over its entire surface. It can be further distinguished from S. ramosa and S. macrantha by the coriaceous upper glume and lower lemma; in S. ramosa and S. macrantha the upper glume and lower lemma are membranous; both species have a pilose upper floret with simple papillae over the NOVON 3: 252-257. 1993. This content downloaded from 40.77.167.99 on Thu, 23 Feb 2017 18:11:27 UTC All use subject to http://about.jstor.org/terms Volume 3, Number 3 1993 Filgueiras et al. Streptostachys rigidifolia Figure 1. Streptostachys rigidifolia Filgueiras, Morrone & Zuloaga. -a. Habit. -b. Schematic longitudinal section of spikelet base, indicating conspicuous thickened internodes: Lg: lower glume; Ug: upper glume; LI: lower lemma; Lp: lower palea; Ul: upper lemma; Up: upper palea; Lo: lodicules; Gy: gynoecium. -c. Spikelet, ventral view. -d. Spikelet, lateral view. -e. Spikelet, dorsal view. -f. Upper palea and lodicules. -g. Upper floret, dorsal view. h. Upper floret, ventral view, lemma and palea. (Based on Bianchetti et al. 634.) 253

Gerritea, a New Genus of Paniceae (Poaceae: Panicoideae) from South America

Gerritea pseudopetiolata of the tribe Paniceae is described and illustrated. Leaf anatomy of this new genus is also included, and relationships with related genera within the Paniceae are discussed. During fieldwork carried out by T. Killeen in 1987, a previously unknown grass was collected at mid elevation in Bolivia, Department La Paz, between Coroico and Caranavi. Additionally, new specimens, previously collected by S. Beck, were found in the herbarium of LPB. Gerritea pseudopetiolata Zuloaga, Morrone & Killeen, gen. et sp. nov. TYPE: Bolivia. La Paz: Nor Yungas on road between Caranavi and Coroico, 16?00'S, 67?30'W, 800 m, 25 July 1987, T. Killeen 2632 (holotype, ISC; isotypes, F, LPB). Figures 1, 2. Gramen perenne, caespitosum; culmis supra nodis profuse ramificantibus, 60-120 cm longis; nodis pilosis. Foliorum vaginae pilosae vel glabrae, 4-17 cm longae. Ligula inferne membranacea, superne ciliata, 0.3-0.6 mm longa. Lamina lineari-lanceolata, 11-27 cm longa, 0.71.5 cm lata, decidua; pseudopetiolo usque 2 cm longo, piloso. Inflorescentiae paniculatae, laxae, diffusae, 14-30 cm longae, 4-12 cm latae. Spiculae ellipsoideae, 1.82.2 mm longae, 0.5 mm latae, longe pilosae; quam gluma infera 3/4-1/ longitudino spiculae aequans, pilosa, 3-nervia; gluma supera 3-nervia. Anthoecia infera neuter: lemma infera 3-nervia; palea infera 0.7-1 mm longa. Anthoecia supera bisexualia, ellipsoidea, 1.3-1.5 mm longa, 0.4 mm lata, membranacea, decidua, glabra; lemma 3-nervia, palea 2-nervia. Lodiculae 2, conduplicatae, glabrae. Stamina 3. Caespitose perennial. Culms rigid, many noded, procumbent, 60-120 cm long, profusely branching at the upper nodes, internodes 4-9 cm long, finely striate, cylindric, pale or tinged with purple, densely pilose toward the distal portion with whitish, appressed hairs; nodes pilose, covered with whitish, long hairs. Leaves mostly cauline. Sheaths longer than the internodes, 4-17 cm long, greenish or tinged with purple, strongly keeled, glabrous or densely papillose-pilose, the margins membranous, ciliate; lower sheaths usually laciniate; auricles small, pilose. Ligules 0.3-0.6 mm long, membranous-ciliate, pilose on the abaxial surface, glabrous on the adaxial surface; collar pilose or glabrous, well defined with a transverse brownish line. Blades linear-lanceolate, 11-27 cm long, 0.7-1.5 cm wide, flat, with a long pseudopetiole up to 2 cm long, articulated at the base and early deciduous, sparsely pilose, the margins scaberulous, the lower ones ciliate with long whitish hairs or glabrous. Peduncle terete, up to 10 cm long, hirsute. Infiorescence a terminal, exserted, panicle, lax, pyramidal, multiflowered, 14-30 cm long, 4-12 cm wide; main axis flexuous, hispid, greenish or tinged with purple; pulvini pilose, firstorder branches divergent; axis of the branches scabrous, sparsely hispid; pedicels up to 8 mm long, flexuous, scaberulous, sparsely pilose, terete. Spikelets solitary, ellipsoid, 1.8-2.2 mm long, 0.5 mm wide, slightly laterally compressed, gaping, greenish or tinged with purple, hispid; upper glume and lower lemma subequal, 3-nerved. Lower glume lanceolate, 1.4-1.9 mm long, 3/4 to 1/ the length of the spikelet, with papillose-pilose hairs up to 7 mm long toward the margins, acuminate, 3-nerved, with a stipe 0.2 mm long below its insertion. Upper glume 1.8-2 mm long, herbaceous, acute, papillose-pilose toward the margins with whitish hairs up to 7 mm long. Lower lemma 1.6-1.7 mm long, glumiform, acute, glabrous. Lower palea ovate-lanceolate, 0.7-1 mm long, 0.1-0.2 mm wide, membranous, hyaline, the margins scaberulous, 2-nerved; lower flower absent. Upper anthecium narrowly ellipsoid, 1.3-1.5 mm long, 0.4 mm wide, glabrous, membranous, smooth, pale, disarticulating at maturity; lemma 3-nerved, the margins flat, not enrolled over the palea; palea 2-nerved, free at its apex; lodicules 2, conduplicate, truncate, 0.2 mm long, embracing the lower margins of the palea; stamens 3, anthers 0.6-0.7 mm long; styles 2, free; stigmas plumose, whitish. Caryopsis

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

Panicum sciurotoides, a New Species of Panicum (Poaceae: Paniceae) from America

Annual. Culms decumbent, geniculate, rooting and branching at the lower nodes, erect portion 1085 cm tall, branching at the upper nodes; internodes 2.5-11.5 cm long, terete, hollow, hispid to glabrous; nodes dark, compressed, densely pilose with retrorse whitish hairs. Sheaths striate, 3-6.5 cm long, sparsely papillose-pilose to glabrous, the margins ciliate or one margin ciliate and the other one membranous. Ligules membranous-ciliate, small, surmounted by long hairs at the base of the blade; collar pilose. Blades ovate-lanceolate, 3-10 cm long, 0.82 cm wide, flat, cordate, amplexicaulous and asymmetric basally, densely hirsute, with short to long appressed tuberculate hairs, to short-hispid on the abaxial surface or glabrous, the margins ciliate toward the base, otherwise scabrous. Inflorescence terminal, lax, diffuse, pyramidal, 2.5-9 cm long, 1.5-8.5 cm wide; main axis wavy, hirsute, with long papillose-pilose hairs; branches alternate, flexuous, the axis of the branches smooth, glabrous; pedicels long, glabrous. Spikelets solitary, long-ellipsoid, 1.5-1.9 mm long, 0.5-0.7 mm wide, greenish, short-hispid; upper glume and lower lemma subequal. Lower glume ovate, 0.4-0.9 mm long, usually /3-/2 or more the length of the spikelet, acute to truncate, 1-3(-7)-nerved. Upper glume 7-9(-1 1)nerved, not embracing the lower lemma. Lower lemma glumiform, 7-9-nerved, acute, not inflated at the base. Lower palea lanceolate to truncate, small, 0.7-1 mm long, 0.2-0.3 mm wide, hyaline, glabrous; lower flower absent. Upper anthecium ellipsoid, 1.2-1.7 mm long, 0.4-0.6 mm wide, smooth, shiny, short-apiculate, with simple papillae over its surface, inserted basally. Caryopsis 1.1 mm long, 0.7 mm wide.

Novelties in Panicum Subg. Dichanthelium Sect. Dichanthelium (Poaceae: Panicoideae: Paniceae)

Short-rhizomatous perennials. Culms decumbent to geniculate, then erect, 45-120 cm tall, branching at the upper nodes, scandent; internodes compressed to cylindric, 7-13 cm long, glabrous; nodes compressed, glabrous, brownish. Sheaths 4-10.5 cm long, shorter than the internodes, glabrous to papillose-pilose toward the base, shiny, one margin ciliate, the other one ciliate toward the base, otherwise glabrous. Ligules 0.2 mm long, membranousciliate; collar pilose. Blades linear-lanceolate, 5-12 cm long, 0.6-1 cm wide, glabrous to short-hispid, attenuate at the base and apex, the margins scabrous, long-ciliate toward the base; midnerve conspicuous. Inflorescences terminal, exserted; panicles lax, diffuse, 3.5-15 cm long, 3-10 cm wide; main axis with or without glands, wavy, glabrous, the pulvini glabrous; first-order branches ascendent, whorled toward the base, then subopposite or alternate, the axis of the branches glabrous, flexuous, with or without glands; pedicels triquetrous, glabrous, with or without glands. Spikelets narrowly ellipsoid, 1mm long, 0.8 mm wide, glabrous, greenish, non-stipitate; upper glume and lower lemma subequal, the nerves manifest. Lower glume ovate, 0.9-1.3 mm long, 2%-l/2(-3) the length of the spikelet, not embracing the upper glume, (l-)3-nerved, the lateral nerves inconspicuous. Upper glume 1.62 mm long, not covering the apex of the upper anthecium, 9-nerved. Lower lemma glumiform, 1.82.1 mm long, 9-nerved. Lower palea lanceolate, 1.5-1.8 mm long, 0.4 mm wide, shortly pilose near the apex, otherwise glabrous, hyaline. Lower flower male; stamens 3 or absent, anthers 1 mm long. Upper anthecium ellipsoid, 1.6-1.8 mm long, 0.7 mm wide, pale, indurate, papillose, the apex of the lemma shortly crestate and pilose. Upper flower bisexual; lodicules 2, covering the lower margins of the palea; stamens 3, the anthers 1.2 mm long, purplish; styles 2, free, stigma purplish. Caryopsis ovoid, 1.3 mm long, 0.7 mm wide; hilum punctiform; embryo less than 34 the length of the caryopsis.

Four New Species of Axonopus (Poaceae: Paniceae) from Tropical America

The following species of Axonopus sect. Axonopus are described: A. rupestris, from Goids, Brazil, A. casiquiarensis from Guainia, Colombia, and Amazonas, Venezuela, A. chimantensis from Bolivar, Venezuela, and A. jeanyae from Cocl&, Panama. Axonopus is a predominantly tropical American grass genus with a few species extending into the American subtropics and the Old World tropics. Black (1963) monographed the genus and recognized 109 species. With continued exploration it has become apparent that new species remain to be described. On the other hand, it is also probable that some of the species recognized by Black must eventually be synonymized as intermediate populations become known. Axonopus belongs to the tribe Paniceae and is distinguished by the absence of a lower glume, lower palea, and lower flower, and by its solitary, dorsally compressed spikelets borne inversely (i.e., with the back of the upper glume facing away from the rachis) in two rows on one or usually several to many racemes. This paper reports on recent fieldwork in tropical America that has brought to light four undescribed species of Axonopus sect. Axonopus. These are published now so that the names will be available for two forthcoming floras, Flora Mesoamericana and Flora of the Venezuelan Guayana.