Monographs Details: Cyphomandra acuminata Rusby
Description:Species Description - Small tree 2-5 m tall. Branches glabrate. Leaf blades simple, unlobed, subcoriaceous, acuminate at apex, glabrous adaxially except for sparse glandular puberulence along veins, glabrous abaxially; petioles glabrescent or occasionally with a few eglandular hairs 2-3 mm long. Trunk leaves simple, unlobed, the blade ovate, 17-24 cm long, 8-13 cm wide, length:width ratio (1.5-) 2-2.5:1, the base truncate to cordate with basal lobes up to 2.5 cm long; petioles 6-13 cm long. Crown leaves 4 per sympodial unit, simple, unlobed, the blade ovate, 6-23 cm long, 3-9 cm wide, length:width ratio (1.5-)2-3(-5): 1, the base truncate to subcordate with basal lobes less than 1 cm long; petioles 1.5-8 cm long. Inflorescence unbranched or forked (rarely further branched), 15-50-flowered, 4-22 cm long; peduncle 1-6 cm long; rachis 3-20 cm long; pedicels 10-15 mm long, in fruit 30-50 mm long, 2-5(-20) mm apart, articulated above the base, leaving pedicellar remnants 1-2 mm long; peduncle, rachis, and pedicels glabrous. Flower buds ellipsoidal, obtuse to acute at apex. Calyx fleshy, glabrous to sparsely glandular-puberulent, the radius 4 mm, the lobes 1-2 mm long, 2-3 mm wide, deltate, apiculate. Corolla purple or reddish, subcoriaceous or fleshy, stellate, the radius ca. 10-15 mm, the tube 3-4 mm long, the lobes narrowly triangular, 8-14 mm long, 2-5 mm wide, glabrous abaxially and adaxially, the margin tomentose, the apex acute. Anther thecae pinkish or purplish, oblong, 3.5-4 mm long, 2 mm wide, the pores directed distally and laterally; connective purple or reddish brown, oblong, 4-6 mm long, 1.5-2 mm wide, abaxially slightly shorter than thecae at apex, slightly exceeding them at base, adaxially present or absent. Ovary glabrous; style glabrous, cylindrical, somewhat dilated apically, 5-7 mm long, 0.6-1.5 mm in diam., about equalling the stamens or exserted up to 2 mm beyond them; stigma truncate or subcapitate, 1-2 mm in diam. Fruit globose to ellipsoidal, obtuse or acute at apex, 2.5-4 cm long, 2-3 cm in diam., glabrous, yellow or orange when mature; mesocarp with stone cell aggregates; seeds 5-9 mm long, 4-7 mm wide, densely dark brown-pilose with hairs ca. 1-2 mm long.
Discussion:Cyphomandra acuminata appears to be most closely related to C. betacea and C. uniloba. Its pinkish, stellate corollas are similar to those of C. betacea, but it differs from the latter species by its nearly glabrous leaves and stems and very large seeds. Hybrids have been produced in the greenhouse between these two species (Bohs, 1991). Cyphomandra acuminata may be one of the closest wild relatives of C. betacea.Cyphomandra acuminata is often almost indistinguishable from C. uniloba on herbarium sheets. Both species occur in nearly the same areas of upland Bolivia. Cyphomandra acuminata is found above 1500 meters, whereas C. uniloba grows at lower elevations. Both species have ovate leaves with cordate bases and sparse, inconspicuous pubescence. However, the leaves of C. uniloba are consistently broader and have deeper basal lobes than those of C. acuminata. Cyphomandra uniloba generally retains some puberulence on the abaxial leaf surfaces and adaxial corolla surfaces, whereas C. acuminata is nearly glabrous at maturity. Living specimens of C. acuminata have darker and glossier leaves than C. uniloba. Fresh flowers of C. acuminata have purplish or reddish corollas, in contrast with the green, yellow green, or whitish corollas of C. uniloba. The connective and anther thecae have a reddish or purplish cast in C. acuminata, unlike the yellowish connective of C. uniloba. The stigma of C. acuminata, although slightly dilated at the apex of the style, is not as broad as that of C. uniloba and lacks the two conspicuous apical glands present in the latter species.Cyphomandra acuminata can be distinguished from all other species in the genus by its unusually large and conspicuously pubescent seeds. Other species with large seeds such as C. hartwegii, C. endopogon, and C. sibundoyensis have whitish seed hairs generally less than 1 mm long.The collection of Plowman and Davis 4929 (F, GH) from Prov. Paucartambo, Dept. Cuzco, Peru may belong to C. acuminata. The fruits and seeds agree with those of C. acuminata, but the leaves have truncate or cuneate rather than cordate bases. Only fruits are present on this collection, and a decision to include it in C. acuminata or segregate it as a different taxon must await additional collections.One of the two sheets of Rusby 2600 at NY annotated by Rusby has been chosen as the lectotype. Unfortunately, neither sheet has fruits or flowers, though Bang 2281, cited by Rusby as a paratype, has both.
La Paz Bolivia South America
| Bolivia South America