Pleroma
(from pleroma, fulness; referring to the cells of the capsule). SYN. Lasiandra. Including Chaetogastra, Melastoma, Micranthella, and Rhexia (in part). ORD. Melastomaceae. A genus containing about 124 species of stove or greenhouse shrubs and sub-shrubs, rarely perennial herbs, sometimes climbing, often strigosopilose or hispid, natives of tropical South America, being mostly Brazilian. Flowers violet or purple, usually disposed in terminal, trichotomously-branched panicles, large, sometimes with concave involucral bracts, very rarely four-parted; calyx tube ovoid, campanulate, urceolate, or elongated; lobes five, as long as, or longer than, the tube; petals five, obovate, often unequilateral and retuse. Leaves frequently large, coriaceous, petiolate, ovate or oblong, entire, three to seven-nerved. The species thrive either in turfy loam or peat, preferably the former, and cuttings of half-ripened shoots root readily in a close frame at almost any time of year when they can be obtained. P. elegans forms a fine exhibition plant when well grown, and P. macranthum is one of the most beautiful subjects for covering a pillar or rafter in a greenhouse or cool stove. A season of rest should be allowed Pleromas in winter; but plenty of water may be applied through the summer. Except where otherwise stated, the under-mentioned species are shrubs, and require stove treatment.
P. Benthamianum (Bentham's).* fl. of a beautiful dark purple, almost white in the centre, about 2in. across; panicles terminal, glanduloso-pilose. Autumn. l. oblong-lanceolate, rounded or somewhat cordate at the base, acute, nine-nerved, entire, the upper surface rough with small setae, the lower covered with adpressed, silky hairs. h. 4ft. Organ Mountains, 1841. (B. M. 4007.) P. elegans (elegant).* fl. rich blue, large, produced in abundance during May and June. l. opposite, ovate-acuminate, bright shining green. h. 5ft. Organ Mountains, 1844. (B. M. 4262.) P. Gaudichaudianum (Gaudichaud's). fl. rosy-purple, in terminal panicles. Summer. l. petiolate, ovate, acuminate, beset with small, softish bristles. Branches tetragonal, rough from small, adpressed bristles. h. 2ft. to 3ft. Brazil, 1836. SYNS. Lasiandra petiolata (B. M. 3766), Pleionema Gaudichaudiana, Rhexia petiolata, and R. petiolaris. P. Gayanum (Gay's).* fl. white, in terminal panicles. Late autumn. l. ovate-oblong, acute, serrate, hairy, h. 1ft. to 2ft. Peru, 1874. Herb. (B. M. 6345.) P. granulosum (granulose). fl. reddish-purple, very showy, almost 3in. in diameter; corolla concave, rotate; petals obovate-oblong, acuminate, shortly apiculate; panicles terminal, with decussate branchlets. l. coriaceous, decussately opposite, entire, attenuated at both ends, five-nerved; petioles much shorter than the leaves. h. 10ft. Brazil. (B. R. 671.) SYN. Lasiandra Fontanesiana (R. G. 1865, 466).
P. heteromallum (one-woolly-sided). fl., petals purplish-violet five or six, obcordate; calyx pubescent, with deciduous teeth; filaments short, conniving. July to September. l. oval-cordate, stalked, beset with flocky wool beneath. h. 4ft. to 6ft. Brazil, 1819. SYN. Melastoma heteromalla (B. M. 2337; B. R. 664).
P. holosericeum (silky). fl. purple; thyrse panicled, terminal, with the rachis very villous and compressed; calyx tubular. July. l. sessile, ovate, five to seven-nerved, entire, densely silky-villous on both surfaces. Branches tetragonal, clothed with adpressed bristles. h. 6ft. to 10ft. Brazil, 1816. A beautiful species. SYNS. Lasiandra argentea, Rhexia holosericea (B. R. 323; L. B. C. 236).
P. Kunthianum (Kunth's). A synonym of P. semidecandrum. P. macranthum (large-flowered).* fl. rich deep violet-purple, about 5in. in diameter, solitary, freely produced at the ends of the branchlets. Winter. l. ovate or oblong-ovate, acuminate, rugose. Branches slender, terete. Brazil, 1864. A very beautiful plant, flowering the more profusely when in a large state, and forming one of the most effective subjects for greenhouse or conservatory decoration. It is best suited for trellises or walls, and, for this purpose, should be planted out, or placed in large tubs or boxes, after the first year's growth. (B. M. 5721.) SYN. Lasiandra macrantha. P. m. floribundum (floriferous). fl. of a rich and brilliant violet-blue, produced almost throughout the year, and measuring nearly 1 1/2ft. in circumference. St. Catherine's, Brazil, 1870. A most beautiful variety, producing its gigantic flowers on young plants when only about 3in. in height. It is better suited for pot culture than the type.
P. sarmentosum (twiggy).* fl. deep violet or violet-purple, upwards of 2in. in diameter, and disposed in trichotomous panicles. l. ovate or ovate-oblong, shortly stalked. Branches sarmentose. h. 1ft. to 2ft. Cool valleys of Peru, 1867. A beautiful, greenhouse, sub-shrubby plant. (B. M. 5629.) P. semidecandrum (five-stamened). fl. purple; petals very obtuse; calyx tube campanulate, rigidly setose; pedicels hispid, axillary, one-flowered, and terminal. July. l. petiolate, oblong, acute, five-nerved, entire, setuloso-scabrous above, villous beneath. Branches tetragonal, and, as well as the petioles, villous. Brazil. SYN. P. Kunthianum (B. M. 4412). P. villosum (villous). fl. rosy-pink, terminal, few, pedunculate; petals obovate, retuse, mucronate. May and June. l. ovate, acute, entire, villous, five-nerved. Branches terete, villous beneath. h. 3ft. to 4ft. 1820. SYN. Melastoma villosum (B. M. 2630; L. B. C. 853).
P. vimineum (twiggy). fl. purple; calyx covered with glandular hairs, the segments lanceolate and mucronate. July and August. l. ovate-lanceolate, acute, petiolate, and, as well as the branches, scabrous, but canescent beneath. h. 6ft. Brazil, 1821. SYN. Rhexia viminea (B. R. 664).