Rapatea yapacana Maguire

• Authority

  Maguire, Bassett. 1965. The Botany of the Guayana Highland. Mem. New York Bot. Gard. 12 (3): 1-285.

• Family

  Rapateaceae

• Scientific Name

  Rapatea yapacana Maguire

• Type

  Type. Hummock-forming perennial in open woodland, frequent, Yapacana Savanna 3, Orinoco River, alt. 125 m, Amazonas, Venezuela, 20 Nov 1953, Bassett Maguire, John J. Wurdack d- George S. Bunting 36584-A (holotype N Y ) . Paratypes. All Yapacana Savanna 3: Maguire, Cowan d Wurdack 30489-A; Maguire, Wurdack d Bunting 36574; Maguire, Wurdack & Maguire 41540.

• Description

  Latin Diagnosis - A R. angustifolia Spruce ex Kornicke et R. circasiana Garcia-Barriga et Mora valde affinis, sed differt bracteolis longi-aristatis. Herbae terrestres perennes vulgo 3-4 dm altae; vaginis compressis, anguste lanceolatis, 6-8 cm longis; laminis anguste linearibus 3-6(-8) mm latis, 2.5-3.5 dm longis, acutiusculis, valde minuteque aspero-papiUatis; pedunculis vulgo 3-4 dm longis; capitulo subhemisphaerico, bracteis involucralibus 2, 3.0--4.5 cm longis, lanceolatis, basibus 1.2-1.6 cm latis; bracteolis non-gradatis, anguste lanceolatis, 10-14 mm longis, 3-nervis, longi-aristatis, arista 2-4 mm longa; granis pollinis subsphaeroidalibus, axibus equatorialibus 35-37.5 µ, axibus polaribus 30-32.5 µ, aperturis zonisulcatis, sporodermis minute scorbieulatis, aperturis verruculatis; seminibus mihi ignotis.

• Discussion

  In the isolated Yapacana Savannas, R. yapacana is common, and the population so developed is of a highly uniform nature.