Supplemental Notes on New World Xyris (Xyridaceae)

Abstract

Of South American Xyris sent to the author for determination by the Missouri Botanical Garden and The New York Botanical Garden, six appear to be new species: three (X. boliviana, X. guillenii, and X. subasperula, sent from MO) are recent collections from eastern Bolivia; two (X. amorimii and X. ferreirae, sent from NY) are Brazilian, from Bahia and Amazonas, respectively. A sixth (X. gongylospica) was collected from the Guayana Highlands of Bolivar, Venezuela. All are described and illustrated, and their relationships are discussed. Of the South American Xyris recently sent to me for determination from the Missouri Botanical Garden and The New York Botanical Garden, five are distinct when one applies existing treatments (Kral, 1988, 1994; Maguire & Smith, 1964; Smith & Downs, 1968) to them. These, and yet another that I found during a trip to the Guayana Highlands of Edo. Bolivar, Venezuela, are presented below. The kindness of curators at the above-mentioned institutions, together with that of the original collectors of the Brazilian and Venezuelan material, is hereby gratefully acknowledged. 1. Xyris amorimii Kral, sp. nov. TYPE: Brazil. Bahia: Mun. Morro do Chapeau, Estrada p/o Morro da Torre de transmissio, ca. de 10 km a partir da Sede do Municipio, ca. 1100 msm, campo rupestre, 22 Fevereiro 1993, A. M. A. Amorim, A. M. V de Carvalho, J. G. Jardim & J. R. da Silva 1048 (holotype, CEPEC; isotypes, NY, VDB). Figure 1. Habitu et spica X. minarum Seubert et affinibus similis, praecipue differt sed basibus foliorum minus dilatatis, bracteis (dum similiter scariosis) et sepalis lateralis distaliter fimbriatis, trichomatibus elongatis, pallidis, crispatis. Perennial, caespitose, smooth, 5-7 dm high. Roots slender, fibrous. Stems short. Principal foliage leaves in narrow fans, 16-26 dm long, longer than the scape sheaths; sheaths entire, carinate, thin, prominently costate, shining, brown to pale red-brown or stramineous, about as long as the blades, distally papillose, at base gradually dilating, upleaf gradually narrowed, eligulate or shortliguled, flattened, narrowly linear, 1-2 mm wide, olivaceous, prominently few-nerved, minutely papillose; apices gradually narrowed, narrowly acute, slightly thickened; margins thin, entire. Scape sheaths red-brown toward base, toward apex open with elongate blades. Scapes straight, slightly twisted, terete, ca. 0.5 mm thick, at apex few-costate, minutely papillate, olivaceous. Spikes multiflorous, turbinate at anthesis, broadly ovoid afterward, 0.71 cm long; bracts erect to ascending, subequal, loosely spirally imbricate, broadly oblong to narrowly ovate, 5.5-6.5 mm long, thin, pale brown, papillate, scarious, the margins toward apex densely white-villous, the dorsal areas prominent, pale green, punctate. Sterile bracts few, with continuous, narrow dorsal areas; fertile bracts emarginate, the dorsal areas narrowly triangular, up to 4 mm long. Lateral sepals free, equilateral, lanceolate, curved, ca. 5 mm long; keel narrow, firm, papillate from base to tip; margins scarious, white-villous toward apex. Petal blades obovate, ca. 4 mm long, acute, undulate-margined, yellow. Staminodia bibrachiate, the branches densely long-penicillate. Anthers oblong, ca. 1.5 mm long, deeply emarginate and sagittate; filaments 0.5-0.7 mm long. Capsule ellipsoid, ca. 3 mm long; placenta central. Seeds numerous, ellipsoid to ovoid, ca. 0.4 mm long, finely spirally multiribbed, translucent. Distribution. Known only from the type collection. This species is distinctive both in foliage and inflorescence, but it is difficult to determine its alliances. In habit and spike it resembles Xyris minarum Seubert and related taxa, yet its leaf bases are less dilated; its spike bracts, while similarly scarious, are fringed distally with long, pale, crisped hairs, a character likewise found on its lateral sepals. These two latter features are unique in that complex. 2. Xyris boliviana Kral, sp. nov. TYPE: Bolivia. Santa Cruz: Velasco Parque Nacional Noel Kempff M., pampa inundada, orilla Rio Itenez, 13o32'37S, 61o01'37W, 200 m, 1 June 1994, E. Gutierrez, R. Quevedo & F Mamani 1345 (holotype, USZ; isotypes, MO, VDB). Figure 2. NovoN 8: 388-398. 1998. This content downloaded from 157.55.39.244 on Fri, 17 Jun 2016 05:09:53 UTC All use subject to http://about.jstor.org/terms Volume 8, Number 4 Kral 389 1998 New World Xyris ?,,. ,! . icm , ,d ..