Monographs Details: Stachyarrhena acutiloba Steyerm.
Authority: Maguire, Bassett. 1965. The Botany of the Guayana Highland. Mem. New York Bot. Gard. 12 (3): 1-285.
Family:Rubiaceae
Description:Latin Diagnosis - Arbuseula; foliis petiolatis, petiolis 2-2.7 cm longis glabris; laminis oblanceolatis apice abrupte hebite acuminatis, acumine 10-12 mm longo 4-5.5 mm lato, basi subacuminatis 14.5-16 cm longis 4.5-5.7 cm latis glabris; nervis lateralibus utroque latere 10-11; inflorescentia mascula spicato-paniculata pendula 15 cm longa, 2-2.5 cm longe pedunculata, rhachi glabra; inflorescentiae ramis inferioribus 2-3 mm longis; floribus plerumque pedicellatis, pedicellis 0.5-1 mm longis, vel supremis sessilibus; calyce masculo breviter campanulato 2 mm longo 3 mm lato apice truncato minute 5-repando-dentieulato extus glabro verruculoso; corolla mascula breviter hypocrateriformi, tubo lobis breviori 3-3.25 mm longo basi 2 mm lato fauce 3 m m lato extus glabro intus parte basilari 2 mm glabro superne hirsutulo, lobis late ovatis subfalcatis apice subacutis 4.5 mm longis 3 mm latis prominente earinatis extus glabris, intus glabris infra medium medio strigosohirsutulo excepto; antheris lineari-oblongis apice aeutis 2.8-3 mm longis, filamentis ca. 1 mm longis.

Discussion:This species is noteworthy in having the eorolla-tube shorter than the lobes, the acute to subacute, carinate corolla-lobes, and acuminate to subacuminate leaf-blades.