New Neotropical Species of Meliosma (Sabiaceae)

Abstract

Meliosma hartshornii A. Gentry, from Costa Rica; M. corymbosa A. Gentry and M. nanarum A. Gentry, from Nicaragua; M. peytonii A. Gentry and M. vasquezii A. Gentry from Peru; and M. solomonii A. Gentry from Bolivia are described. A number of undescribed species of Meliosma have been encountered in the process of preparing the familial treatments of Sabiaceae for the Floras of Nicaragua and Peru and in the course of general identification. Meliosma is a largely warm-temperate to montane-tropical genus with at least 15 Asian and ca. 40 neotropical species. A characteristic but rather nondescript element of many Latin American cloud forests, it is very poorly collected and as a result is poorly known taxonomically. Indeed this paper presents the first report of the genus for Peru. Each of the new species proposed here is represented by several collections, making possible an assessment of patterns of intraspecific variability. In addition to these six species, there are many unidentified Meliosma collections, especially from Peru, that seem to fit none of the described taxa and may belong to as many as ten or more additional new species. Alternatively these additional collections might represent many fewer relatively polymorphic taxa. I have refrained from describing further presumably new taxa in hopes that future collections will provide clearer understanding of specific delimitations. Meliosma hartshornii A. Gentry, sp. nov. TYPE: Costa Rica. Heredia: road to Volcan Barba, 2 km N of Sacramento, 2,750 m. alt, 29 Dec. 1974, G. Hartshorn 1608 (holotype, MO). Arbor usque 15 m alta. Folia oblanceolata vel anguste elliptica, usque 1 1 cm longa et 4 cm lata, domatiis axillaribus pubescentibus. Inflorescentia sparsim adpresso-puberula, pedicellis 1-2 mm longis, forum sepalis 1.5 mm longis, petalis ca. 2 mm longis. Fructus globosus, 0.8-1.0 cm diametro. Tree to 50 cm dbh and 15 m tall; branchlets somewhat angled, glabrous or with a few minute and inconspicuous reddish trichomes, the bark finely longitudinally ridged, with scattered raised lenticels. Leaves alternate to irregularly clustered, oblanceolate to narrowly elliptic, 2-1 1 cm long, 1-4 cm wide, acute to apiculate at apex, cuneate and often somewhat marginally inrolled at base, coriaceous, the 2? and 3? venation subprominulous above and below, the surface minutely and densely punctate above and lepidote-punctate below, glabrous above and below except for conspicuous tufts of simple trichomes in the axils of the lateral nerves below, drying grayish-olive above, olive or brownish-olive with tan main veins below; petiole 0.2-1 cm long. Inflorescence pyramidal-paniculate with a welldeveloped central axis, 8-17 cm long, usually opposed to a subterminal leaf or short branch, appearing more or less terminal, glandular-papillose and also sparsely appressed-puberulous, the thick pedicels 1-2 mm long. Sepals 5, ovate, ca. 1.5 mm long, glandular-papillose, the margin strongly ciliate; petals mostly caducous and missing on type, ca. 2 mm long; stamens with slender 2 mm long filament, the bottom half fused with the bottom half of the narrow inner petal, the anthers subglobose, ca. 0.6 mm long, subtended by the thickened connective; ovary ovoid, ca. 1 mm long, densely puberulous, the style linear, 1 mm long. Fruit red when fresh, globose, 0.8-1.0 cm in diameter, not stipitate, sparsely puberulous with flexuous trichomes when young, essentially glabrate, 1-seeded, 0.8-1.0 cm in diameter. Apparently endemic to the cloud forests of Volcan Barba between 2,700 and 2,800 m. Additional collection examined. COSTA RICA. HEREDIA: road to Volcan Barba, 1.5 km N of Sacramento, 2,700 m; tree 50 cm dbh, 15 m tall, fruit red, 27 Jul. 1975, Hartshorn 1759 (MO). I The field work that resulted in discovery of several of the new species described here was supported by grants from the National Science Foundation (DEB-75-20325; DEB-8006253) and USAID (DAN-5542-G-SS-108600). 2 Missouri Botanical Garden, P.O. Box 299, St. Louis, Missouri 63166. ANN. MissouRI BOT. GARD. 73: 820-824. 1986. This content downloaded from 207.46.13.156 on Sat, 10 Sep 2016 06:11:40 UTC All use subject to http://about.jstor.org/terms 1986] GENTRY-MELIOSMA 821 This species is distinctive in the genus in its small leaves and smallish fruits. It is closely related to M. irazuensis Standl., known only from the type from Volca'n Irazui. The main difference is in the larger, pedicellate flowers of M. hartshornii as opposed to the tiny (< 1 mm long) sessile flowers of M. irazuensis. The inflorescence of M. irazuensis differs in being narrower, having simple lateral branches with more crowded sessile flowers, and, especially in the very different, much denser pubescence of erect reddish trichomes. Vegetatively that species apparently can be distinguished from M. hartshornii by its narrower oblanceolate leaves and pubescent young branches. Another small-fruited, usually smallleaved relative of M. hartshornii is M. idiopoda Blake, common at somewhat lower elevations in Costa Rica and Chiriqui. The material of M. hartshornii was originally identified as a variant of M. idiopoda, but its much thicker inflorescence branches and pedicels, larger flowers, thicker more coriaceous leaves, and consistently larger fruits distinguish it from that species. Meliosma corymbosa A. Gentry, sp. nov. TYPE: Nicaragua. Matagalpa: Cordillera Darienense near Aranjuez, 15 km N of Matagalpa, 1,400 m alt., lower montane moist forest; tree 20 m, 12 Aug. 1977, Neill 2342 (holotype, MO; isotypes, HNMN, to be distributed). Arbor usque 20 m alta. Folia oblanceolata vel anguste elliptica, 5-13 cm longa, 1.4-4 cm lata, glabra. Inflorescentia terminalis, corymboso-paniculata, puberula, florum sepalis minus quam 1 mm longis. Fructus asymmetrice subglobosus, 1.6-1.8 cm longus, 1.51.6 cm latus. Tree 20 m tall, the branchlets somewhat angled, glabrous, the bark very finely longitudinally ridged. Leaves irregularly arranged, in part opposite or subopposite, always in part clearly alternate, oblanceolate to very narrowly elliptic, 5-13 cm long, 1.4-4 cm wide, acute at apex, narrowly cuneate at base, coriaceous, entire, drying dark above, olive brown below, the lateral veins plane and inconspicuous above, prominulous below, completely glabrous except for a very few scattered and inconspicuous lepidote or stellate-lepidote trichomes below; petiole slender, indistinctly demarcated from the tapering leaf base, ca. 0.5-2 cm long, glabrous except for a very few minute and inconspicuous scales. Inflorescence terminal, corymbose-paniculate, flattopped and greatly exceeding the uppermost leaves, dense, puberulous with tiny suberect, reddish trichomes, ca. 10 cm long and 15 cm accross, the flowers ultimately on short pedicels, mostly ca. 1-2 mm long. Sepals 5, ovate, minute, less than 1 mm long, glandular-lepidote, the margin minutely ciliate; outer petals broadly ovate, ca. 2 mm long but the rounded apex inrolled, ca. 1.5 mm wide, the inner ones narrow, ca. 2 mm long; fertile stamens 2, the anther thecae thick and suborbicular, ca. 0.5 mm long, subtended by the broad connective; staminodes 3, ca. 1 mm long; ovary ovoid, ca. 1 mm long, merging with the short style. Fruit asymmetrically subglobose, 1.6-1.8 cm long and 1.5-1.6 cm wide, shortstipitate, minutely glandular-papillose, otherwise glabrous, 1-seeded. Apparently endemic to the montane forests of north central Nicaragua in Matagalpa and Jino-