Begonia robusta Blume

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Begonia Section

  • Platycentrum

Additional Publications

  • Hasskarl, Pl. Jav. Rar. 242 (1848); Candolle, Prodr. 15(1): 275 (1864); Koorders, Exkurs.-Fl. Java 2: 646 (1912); Doorenbos, Begonian 47: 213 (1980); Tebbitt, Begonias 204 (2005); Tebbitt, Blumea 50(1): 155 (2005).

Description

  • Erect shortly rhizomatous subshrub to 2 m tall. Stems, leaves, and outer surfaces of tepals with a dense covering of long red or white hairs.

    Stipules persistent, lanceolate to ovate, 1-3.7 × 0.9-2.4 cm. Leaves: petiole green, 10-40 cm long, joining blade at an angle; blade above green, beneath grayish green, in outline ovate to almost circular, 10-25 × 10-35 cm, usually irregularly five- to eight-lobed, sometimes almost entire, especially in young plants, lobes narrowly to broadly triangular, to 7 cm long, margin of lobes entire, base cordate, veins palmate.

    Inflorescence: axillary, short, 12-22-flowered, bisexual, cymose; bracts soon falling, broadly elliptic to obovate, 0.6-2.5 × 0.2-1 cm.

    Male flowers: tepals four, white to pink, outer pair broadly elliptic, 0.8-1.6 x 0.7-1.2 cm, inner pair elliptic, 0.7-1.7 × 0.5-0.9 cm; stamens 65-75, arranged symmetrically, anther connectives projecting.

    Female flowers: bracteoles absent,; tepals five, white to pink, elliptic to obovate, 0.9-2 × 6.5-1.1 cm; ovary fleshy, green, almost spherical, 0.7-1.5 cm in diameter, unequally 3-winged, one wing much longer than others, three-locular, placentae axile, bifid; styles three, once branched, stigmas in spiraled band. (Tebbitt, M.C. 2005: Begonias: Cultivation, Identification, and Natural History)

Chromosome Numbers

  • 2n = 88. (Tebbitt, M.C. 2005: Begonias: Cultivation, Identification, and Natural History)

Habitat

  • Rainforests, 1100-2600 m asl.

Conservation

  • Proposed IUCN category: LC. Widespread. (Hughes, M. An annotated checklist of Southeast Asian Begonia. 2008)

Distribution

Asia-Tropical: Jawa (Jawa present); Lesser Sunda Is. (Lesser Sunda Is. present); Sulawesi (Sulawesi present); Sumatera (Sumatera present)
Indonesia: Sumatra, Java, Lesser Sunda Isles (Bali), Sulawesi.

See Specimens tab for map of point distribution data of georeferenced specimens.

Notes

  • At their most "typical" form, B. robusta may be distinguished from B. multangula thus (Tebbitt, 2005):
    - B. robusta: Leaf blades above with long red glandular hairs, margin entire or with short rounded lobes; peduncle of infructescence usually at least four times longer than the pedicels; fruit usually with one longer wing and two shorter wings or ribs.
    - B. multangula: Leaf blades glabrous above or with short to long white or red glandular hairs, margin with several short angular lobes; peduncle of infructescence usually less than three times as long as the pedicels; fruit with three equal ribs or short thickened wings.
    However, many intermediate (possibly hybrid) specimens exist. (Hughes, M. An annotated checklist of Southeast Asian Begonia. 2008)