Monographs Details: Macrocarpaea piresii Maguire
Authority: Maguire, Bassett. 1978. The botany of the Guayana Highland--part XI. Mem. New York Bot. Gard. 32: 1-391.
Family:Gentianaceae
Description:Latin Diagnosis - Frutex vel arbor parva, ad 5 m alta; ramis teretibus, internodiis vulgo 3-5 cm longis; foliis appositis, petiolatis, stipulis in annulis 2-4 mm altis connatis; petiolis ca 20 mm longis; laminis glabris rotundatis vel late ovatis, apiculatis, apicibus et basibus obtusis, vulgo 9-12 cm longis, 6-9 cm latis, subcoriaceis, valde pinnatinervis, aliquantum rugosis; inflorescentns amplis, foliari-bracteatis; calyce 8-10 mm longo, tubo ca 2-3 mm longo, lobis 5, oblongis, obtusis, 5-8 mm longis, scario-minute fimbriato-marginatis; corolla infundibuliformi, lobis 5, ovato-oblongis; staminibus 5, filamentis ad juncturam tubi et Umbi affixis; antheris oblongis, 6-7 mm oblongis, 4-locularibus, basifixis, sagittatis, appendicibus caudatis, ca 2 mm longis; granis pollinis singularibus, sphaeroideis, 35-37 µm diam, tricolporatis, colpis profunde prominentibus, sporodermate reticulato, muris continuis, integris, tenuibus; ovario biloculari; placentatione axiale, ovulis numerosis; stylo 8-10 m m longo, stigmatibus 2, lamellatis, late ovatis, minute fimbriatis; capsula seminibusque ignotis.

Distribution and Ecology - Distribution. Known only from the type collection, Serra da Neblina, Amazonas, Brasil, Maguire, Pires & Maguire 60453.

Discussion:4. Macrocarpaea piresii Maguire, sp nov Fig 62L-M, 66, 67. Type. Shrub or small tree to 5 m high, flowers green, occasional in woodland, trail to Pico Phelps, 8000-8500 feet alt, Serra da Neblina, Amazonas, Brasil, 2 Dec 1965, Bassett Maguire, Joao Murga Pires & Celia K. Maguire 60453 (holotype NY, isotypes NY, MG, VEN, US). Macrocarpaea piresii is most closely related to M. neblinae, but has larger flowers and more prominently veined subrugose leaves. Its leaves are similar in venation to those of M. rugosa, but in this species the leaf blades are cordate basally, and the flowers are smaUer with the calyx lobes shorter than the tube.