Stegolepis choripetala Maguire
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Authority
Maguire, Bassett. 1965. The Botany of the Guayana Highland. Mem. New York Bot. Gard. 12 (3): 1-285.
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Family
Rapateaceae
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Scientific Name
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Type
Type. Post flowering, spikelets radiate; caudex to 15 cm thick, 1.5 m high leaves to 2.5 m long; best developed in wet breaks of terrace escarpments, Campo Grande, frequent at alt. 1500 m, Cerro Sipapo (Paraque), Amazonas, Venezuela, 10 Dec 1948, Bassett Maguire d Louis Politi 27573 (holotype, N Y ) . Paratypes. Cerro Sipapo: Herb to 3 m tall, frequent border scrub bush at alt. 1500 m, Maguire & Politi 28575; infrequent, stream banks at alt. 1400 m, Maguire & Politi 28118; frequent marshy places at alt. 2000 m, Maguire d Politi 28355; Sabana Grande at alt. 1500 m, Maguire d Politi 28695.
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Description
Latin Diagnosis - Herbae perennes terrestres 2-3 m altae; caudicibus erassis carnosis 0.5-3.0 dm longis; foliis 5-9 distichis; vaginis conduplicatis equitantibus, in uno piano dispositis, 20-30 cm longis, 5-6 cm latis, coriaceis, eligulatis, scarioso-marginatis, basim marginis plus minusve 1 cm latis, non-evidentur nervatis; laminis 7-25 dm longis, 3.5-5.0 cm latis, subtiliter 80-100-nervatis, apice falcato subacute, costa prominenta; pedunculis axillaribus 5-7 per lamina, ferme 8-12(-18) d m longis, 2-3 mm erassis, in sieco sulcatis, sursum compresso-dilatis 3-4 mm latis; capitulis compressis, 15-18 (-30)-floribus, 2-3-seriatis; spieulis ca. 15 mm longis, sepalis inclusis; bracteolis 12-14-gradatis, exterioribus 2 mm longis, 3 mm latis, orbieulari-obovatis, obtusis, leviter 3-nervatis, apice subcucullato, interioribus late elliptico-lanceolatis, 5.0-6.5 mm longis, obtusis, leviter 5-nervatis; sepalis liberis oblongo-lanceolatis, subacutis, naviculoideis 9-10(-12) mm longis, leviter 7-9- nervatis, basi 2-3 mm membranacea; petalis 8-10 mm longis, unguibus 4—5 mm longis, 2.5-3.0 mm latis, carnosis, papillosis; laminis 4-5 mm longis, lanceolatis, ca. 3 mm latis, delicatis, aeutis minute auriculatis, margine minute crispo; filamentis liberis 4-5 mm longis, uninervis ca. 1.5 mm latis, antheris ca. 5 mm longis sursum angustatis, 4-locularibus, ad basim brevi-auriculatis, poro minuto oblique apicale; ovario 3-loculare, loculis pluriovulatis; stylo trigono acuto; capsulis obovatis ca. 6 mm longis, ad basim membranaceis, sursum induratis, endocarpo crasso, separate ex exocarpo; seminibus 7-8 per loculo, ca. 1 mm diam, valde adpressis angulatis, testa laxa, membranacea pallida.
Distribution and Ecology - Distribution. Known only from the summit of Cerro Sipapo, Amazonas, Venezuela, but there of wide distribution.
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Discussion
Stegolepis choripetala is quite common on the summit of Cerro Sipapo, sometimes occurring densely about the edge of the cumbre. In higher thickets the plants attain the considerable height of 3 meters. This Sipapo species is most closely related to S. parvipetala Steyerm., known only from Ptari-tepui in the eastern Gran Sabana region, in which the corolla is connate into a tube, and the flowers and heads considerably larger. S. choripetala further seems to be the connecting link with the segregate genus Epidryos because of separable endocarp and small anthers that dehisce by a rounded obliquely apical pore.