Macairea rufescens DC.

  • Authority

    Renner, Susanne S. 1989. Systematic studies in the Melastomataceae Bellucia, Loreya and Macairea. Mem. New York Bot. Gard. 50: 1-112.

  • Family

    Melastomataceae

  • Scientific Name

    Macairea rufescens DC.

  • Description

    Species Description - Shrub, 1-2 m tall; branchlets, petioles, peduncles, and mid-veins on the lower leaf surface hirsute to sericeous with long subulate hairs, with globose sessile glands. Leaves broadly elliptic, 7- 15 X 4-7 cm, basally and apically obtuse, 3-nerved, pseudo-pinnately veined, mid-vein thick and raised, the lateral primary veins arising at the blade base, inconspicuous and close to the margin, upper surface smooth, lower surface sparsely hirsute with long subulate white hairs which are apically frayed, the areoles with sessile glands in a matrix of short, few-branched hairs; petioles 1.5-2.5 cm long. Inflorescence a many flowered terminal paniculate cyme. Flowers with pedicels 2-3 mm long; pedicels, bracts, hypanthium, and calyx lobes sericeous with rust-colored slightly curled hairs, with sessile glands; hypanthium 3.5-4 X 1.8-2.2 mm; calyx lobes triangular, (2-)3(-4) mm long; petals basally white, tuming red with age, apically pink, 9-13 X 6-7 mm; filaments 8.5-9 or 6-7 mm long, ventrally with short-stalked glands; thecae 3.5-4.5 mm long, the connective prolonged and expanded dorsi-basally; ovary apically with glandular hairs, 4-locular. Fruit capsular. Seeds ca. 0.8 mm long, subcochleate.

  • Discussion

    Type: Colombia. Amazonas: Araracuara Mountains (fr), Martius 3156 (holotype: M!, F photo neg. 6340!; isotype: M!).

    Figs. 23B, 29A-D, 34.

    Macairea rufescens is distinguished from all other species by its large, leathery, pseudo-pinnately veined leaves. Such venation has arisen several times, independently, within the Melastomataceae, for example, in Henriettella squamata Alain (Miconieae) and in several species of Graffenrieda (Merianeae).

  • Distribution

    Macairea rufescens occurs on granitic substrates (lajas) along the Rio Guainia (Venezuela) and on Roraima sediment near Araracuara (Colombia); it has recently been collected near Iquitos (Peru).

    Venezuela South America| Colombia South America| Peru South America|