Erisma gracile Ducke

  • Authority

    Andersson, Lennart. 1998. A revision of the genus (Rubiaceae--Cinchoneae). Mem. New York Bot. Gard. 81: 1-75.

  • Family

    Vochysiaceae

  • Scientific Name

    Erisma gracile Ducke

  • Description

    Species Description - Tree 8—25 m high, to ca. 60 cm dbh; hairs yellowish where present; young twigs pubescent. Leaves opposite; blade chartaceous, elliptic or narrowly elliptic, 6.5-10.5 X 2.3 - 4.3 cm, glabrous; apex acuminate; base acute to subobtuse; midvein sulcate above, prominent below; lateral veins ca. 7-9 pairs, angle with midvein 60-70°; tertiary veins randomly reticulate; marginal vein 2-5 mm from margin; petiole canaliculate, 6-7 mm long; stipules absent. Inflorescences terminal, to 12 cm long, peduncles and lateral branches pubescent: cincinni with 3-6 flowers, to 1.5 cm long, densely tomentose; outer bracts subor- bicular, ca. 4 X 4 mm; inner bracts linear, 0.5-1 mm long; pedicels 0.5-2 mm long; buds 3-1 mm long; spurred calyx-lobe ca. 5 mm long; spur globose, ca. 1 mm diam.; other calyx-lobes 1-5 mm long; petal yellow, obcordate, unguiculate, ca. 10 X 8 mm; stamen ca. 6 mm long; style ca. 5 mm long, pilose at base. Fruits winged, glabrous, 4.5-5 cm long; major wing oblong, 3.5-4.5 X 1-1.3 cm; second major wing 1.5-2 X 0.8-1 cm.

  • Discussion

    This species is easily recognized by its chartaceous leaves with sulcate midvein on the upper surface, and small, yellowish-tomentose flowers; the calyx spur is characteristically globose. Its flowers are comparable in size only to the flowers of E. micran- thum, which is, however, an unrelated species, distinguished by the grayish indument and larger, coria¬ceous leaves with prominent midvein on the upper surface. In E. gracile, the outer bracts are persistent and overlap the buds, whereas in E. micranthum, they are small and deciduous. Erisma gracile could be confused with young forms of E. laurifolium, but they are distinguished from each other by the texture of the leaves and especially by the spur morphology. In E. laurifolium, the leaves are coriaceous and the spur is cylindric.