Monographs Details: Pachyloma pusillum Wurdack
Authority: Maguire, Bassett & Wurdack, John J. 1964. The botany of the Guayana Highland--Part V. Mem. New York Bot. Gard. 10: 1-278.
Family:Melastomataceae
Description:Latin Diagnosis - A congeneribus differt foliis uninervatis basi attenuatis. Suffrutex ad 25 cm altus non vel vix ramosus; caulis glaber vel primum sparsissime glanduloso-setulosus demum glabratus. Folia sessilia vel vix (ad 1 mm) petiolata glabra 2.5-5.5 X 0.3-0.7 cm lanceolato-elliptica apice basique acuta coriacea (i.s. longitudinaliter striata) uninervata ad margines vix incrassata integra. Flores terminales solitarii vel terni non pedunculati; pedicelli ad anthesim ca. 2 mm longi demum ad 10 mm elongati ad medium bibracteolati (bracteolis 2-3 mm longis lanceolatis) bracteolis hypanthiisque sparse glandulososetulosi. Hypanthium 5 m m longum; calycis lobi ca. 1 mm longi ovati glandulosoeiliolati. Petala ca. 9 X 4.5 mm elliptica apice acuta apicem versus sparse glanduloso-ciliolata. Stamina isomorphica; filamenta 7 mm longa glabra; antherarum thecae 4 mm longae, connectivo basi 1.8 mm prolongato ventraliter cum appendice bilobulata 0.8 mm longa lataque postice ad basim ipsam cum Cauda 1.8 mm longa. Stylus ca. 1 cm exsertus; ovarium apice sparse glandulosopuberulum.

Discussion:

Fig. 66, a-c.

Type. Flowers pink, rare in Savanna No. 3, northwest base of Cerro Yapacana, Rio Orinoco, Terr. Amazonas, Venezuela, alt. 125 m, 17 Mar 1953, Bassett Maguire & John J. Wurdack 34516A (holotype NY). Paratype. Same locality, Maguire, Cowan, cC Wurdack 30564 (fruiting).

While the material cited is very scanty, the vegetative distinctness of P. pusillum from the other congeners is ample for diagnosis. Only a single flower (not dissected) is available on the unicate holotype; the petal and anther dimensions were derived from dropped parts of this flower. The other species of Pachyloma have 3-5-nerved leaf blades; the dried leaves of P. pusillum. are longitudinally ridged but without any lateral primary veins.