Mouriri sideroxylon Sagot ex Triana

Authority

Morley, Thomas. 1976. Melastomataceae tribe Memecyleae. Fl. Neotrop. Monogr. 15: 1-295. (Published by NYBG Press)

Family

Melastomataceae

Scientific Name

Mouriri sideroxylon Sagot ex Triana

Type

Type. P. A. Sagot 924 (holotype, P; isotypes, BM, BR, F-frag., K, MIN, NY, S, U, W). French Guiana, Acarouany. Flower, June 1856.

Description

Description - Tree to 28 m high, sometimes small and shrub-like, the trunk to 40 cm in diam; plants glabrous except for the inflorescence; young twigs terete to narrowly 4-winged; bark thin, peeling; wood dark brown to reddish, hard and heavy. Petioles 1.0-3.0 mm long; blades tending to be thick, 3.5-15.0 cm long, 2.3-6.0 cm wide, 1.4-2.8(-3.1) times as long as wide, ovate-elliptic to elliptic to ovate or somewhat oblong, abruptly acuminate to short-acuminate to acute at the apex, cordate at base; midrib plane to low-rounded above, sometimes with a shallow groove on each side, prominent below, sharply 2-angled or narrowly 2-winged; lateral nerves invisible to conspicuous above and below when dry. Midrib xylem tubular; stomatal crypts Type III, averaging in a leaf ca 45-117(-144) µ in diam, 20-58 µ high, (16-)27-96 per sq mm (extremes 30-200 µ diam, 17-75 µ high, 15-150 per sq mm), often having prominent papillae on the roof; upper epidermis sometimes one cell thick, sometimes varying irregularly from one to two cells thick in the same leaf, mucilaginous walls frequent in the cells contacting the palisade layer; hypodermis none; free stone cells present along the length of the midrib but thin-walled toward the end; terminal sclereids stellate to columnar, the central bodies when present roundish to rectangular, l-3(-4) times as long as wide, seldom branching, with short arms, the sclereids varying greatly from collection to collection, in some mostly stellate, in some variable, in others all columnar, the thicker leaves having more columnar sclereids. Inflorescences at leafless nodes of twigs up to 7.0 mm thick or rarely in the lower axils, 1-ca 7 per side, often congested with very short lower internodes, each 1-7-flowered, 2.0-11.2 mm long to base of farthest pedicel measured along the axes and with 1-3 internodes in that length; bracts 1.3-2.2 mm long, ovate to triangular, acute to acuminate, mostly deciduous by deflorescence. Axes of inflorescence, bracts, and pedicels more or less minutely puberulent True pedicels yellow to red, 4.5-10.0 mm long; calyx including inferior ovary yellow to whitish, sometimes faintly suffused with purple, 4.3-7.0 mm long, campanulate; free hypanthium 2.2-2.7 mm long; calyx lobes before anthesis 0.7-1.2 mm long, 1.8-2.6 mm wide, 1.3-2.6 mm long from the stamen attachment, triangular to broadly rounded and apiculate, splitting apart at anthesis a further length of 0.4-1.8 mm. Petals mostly pink, sometimes white, purple, or "yellow rosy," 5.0-8.0 mm long, 3.5-6.8 mm wide, ovate or broadly so, acute or abruptly so at apex, clawed at base and often cordate with the blade extended into a lobe on each side of the claw. Filaments white to pink, the antesepalous ones 4.5-7.0 mm long, the antepetalous ones 5.0-10.0 mm long; anthers yellow, purple, or black, 2.9-3.7 mm long; sporangia 2.8-3.4 mm long, dehiscing by apical pores; gland 0.9-1.2 mm long, 2.1-2.4 mm from apex of anther when measured from center of gland; cauda 0.3-0.8 mm long. Ovary 4-5-locular; placentae basal in each locule, the locules sometimes moderately separated and the placentae almost basal-parietal or in other cases the placentae almost axile-basal, the ovules borne on all sides of a short basal column, 5-7 per locule, 20-35 in all; style 11.0-18.0 mm long. Fruit yellowish to red, 1-4 seeded, oblong or subglobose when 1-seeded, wider than thick or depressed-globose and moderately lobed according to the number of seeds when these more than 1, crowned with the hypanthium and often some calyx lobes, the hypanthium sometimes brought to within 60° of the pedicel through unequal development of the ovules when seeds are 1 or 2, the fruit (5.0-)9.0-12.5 mm high excluding hypanthium and (6.0-) 12.0-17.0 mm thick when dry, estimated (6.0-)11.0-16.0 mm high and (7.5-) 15.0-22.0 mm thick when fresh; the figures in parentheses all refer to the collection Maguire et al 30502. Seeds brown, polished, irregularly spheroid but flattened on the contact faces when more than 1, 4.5-9.5 mm high, 4.5-9.0 mm wide, with a rough broad roundish basal hilum 2.5-8.0 mm in diam.

Discussion

This species is one of the more variable ones. Part of its variability appears to derive from its response to different habitats; in good situations large trees may be formed, while in poor sites the plants tend to be stunted and bushy with small parts. Two collections of the latter type are Maguire et al 30502 and ñres 1032, noted respectively as from scrub forest and caatinga. The result is an unusually great range for the species in size of leaves, flowers, fruits, and seeds. The variation in placentation was noted in the discussion of the section. Leaves of Guyana plants in particular tend to be leathery and with shiny upper surfaces even when dry. Further study is required accurately to assess the variation in the species.

Common Names

yoo-koo-ro-a-peé, Guaratarillo, mamoriballi, Mamuriballi, dauicu

Distribution

Colombia at the border of Amazonas, Venezuela; Venezuela in Amazonas, Bolivar, and Delta Amacuro; Guyana; French Guiana; and Brazil in northern Amazonas and northern Pará. Moist forests above flood level, the forest reported once as primary, never as secondary, sometimes as scrub or caatinga, the soil sandy, clayey, or lateritic, the elevations up to 1200 m.

Vaupés Colombia South America| Amazonas Venezuela South America| Bolívar Venezuela South America| Delta Amacuro Venezuela South America| Guyana South America| French Guiana South America| Amazonas Brazil South America| Pará Brazil South America|