Monographs Details: Platycarpum decipiens Woodson & Steyerm.
Authority: Maguire, Bassett & Wurdack, John J. 1964. The botany of the Guayana Highland--Part V. Mem. New York Bot. Gard. 10: 1-278.
Family:Rubiaceae
Description:Species Description - Petioles 1-2 cm long; gland at base of petiole semi-lunar, 1-1.25 mm long; leaf-blades 2.5-4.7 cm wide; lateral pairs of nerves 11-16; inflorescence 9-17 cm long, slightly longer than broad to 1 1/2 times as broad as long or as broad or broader than long, upper secondary lateral branches of the peduncle 2.5-3 cm long, lower ones 4.5-6 cm long, 15-42-flowered, lateral secondary branches (except the lowest) and ultimate pedicels cinereous-strigillose with sparse to moderate ascending-spreading rufous hirtellous pubescence; lower half of main central peduncle glabrous and glaucous, as are sometimes also the lowest lateral secondary branches; calyx-lobes 5, subequal, sericeous within, tomentose without with strigose hairs; corolla somewhat zygomorphic, white, inside crimson-streaked with one yellow lobe (teste Wurdack dc Adderley), the one yellow lobe densely tomentose within, the other four lobes glabrous within, densely barbate zone at base of swollen and enlarged filaments; corolla 21-23 mm long, tube 4 mm long, glabrous within at very base, enlarged abruptly above the tube to a spreading limb 6-12 mm long, 15-17 mm broad at orifice, densely buff-strigose or sericeous without; corolla-lobes slightly less than one-half to slightly more than one-half length of corolla, one of them tomentose within cut usually more deeply along one side (up to 16 mm long) while 12-13 m m long on other side, the other four lobes more or less similar and cut to 9-13 mm long, the lobes mainly 5-6 mm wide, subacute or subobtuse; stamens 5, somewhat unequal, three generally slightly higher than the other two; filaments curved, glabrous, swollen or enlarged at very base, 6.5-8 mm long; anthers versatile, glabrous, 4 mm long with prominent obtuse appendage protruding at apex; shortest two stamens present generally on either side of the lobe which is densely tomentose within.

Discussion:

Fig. 76, D-H.

At the time of publication of the original description of this species, no calyx or corolla was available for study. The excellent flowering material, recently collected by Wurdack & Adderley 43226, furnishes the following emended description to be added to the original publication.