Heteroaridarum borneense M.Hotta

First published in Acta Phytotax. Geobot. 27: 63 (1976)
This species is accepted
The native range of this species is Borneo (Sarawak). It is a subshrub and grows primarily in the wet tropical biome.

Descriptions

Extinction risk predictions for the world's flowering plants to support their conservation (2024). Bachman, S.P., Brown, M.J.M., Leão, T.C.C., Lughadha, E.N., Walker, B.E. https://nph.onlinelibrary.wiley.com/doi/full/10.1111/nph.19592

Conservation
Predicted extinction risk: threatened. Confidence: confident
[AERP]

CATE Araceae, 17 Dec 2011. araceae.e-monocot.org

Habitat
Rheophytic on sandstone boulders and wet cliffs in deep shade.
Diagnostic
This species is unique in the Schismatoglottideae in having distichous leaves held in more or less horizontal fans. A striking convergent example in Araceae is Homalomena geniculata M. Hotta, also from Sarawak.
General Description
Rheophytic herb 30–60 cm tall. Stem condensed, c. 4–10 cm long, c. 2–3 cm diam. Leaves c. 5 together, distichous, held in a more or less horizontal fan; petiole (4–)6–40 cm long, 0.2–1 cm diam., sheathing at the extreme base, the wings extended into a very narrowly triangular ligular portion 6–20 cm long which dries reddish brown; blade narrowly elliptic to oblong elliptic, 9–32 cm long × 2.5–11 cm wide, coriaceous, mid- to dark green adaxally, paler abaxially, the base cuneate, the apex acute to broadly acute and apiculate for 0.5–1.4 cm; midrib abaxially prominent, with 4–9 primary lateral veins on each side diverging at c. 45° and running to a marginal vein; secondary venation adaxially obscure, abaxially faint; tertiary venation forming an inconspicuous tessellate reticulum. Inflorescence solitary, usually nodding; peduncle subequalling the petioles. Spathe 6–8.5 cm long, broadly ovate, apiculate for c. 1 cm, not constricted, the lower c. ⅓ green, convolute and persistent, the upper part white, gaping and then caducous. Spadix subcylindric, blunt, 4–6 cm long, 0.8–1 cm diam.; female zone c. 2 cm long, obliquely adnate to the spathe at the base; pistils crowded; ovaries globular to slightly ellipsoid, 1–1.2 mm diam., with basal and apical placentas, the basal placenta bearing numerous orthotropous ovules, the apical placenta naked or with abortive ovules; stigma sessile, discoid, almost as wide as the ovary, centrally impressed, minutely papillate; interpistillar staminodes absent from among the pistils, confined to one or two irregular whorls at the base of the female zone, stipitate, slightly capitate, about as high as the pistils; sterile interstice a few to several whorls of sterile stamens with centrally impressed tops c. 0.4 mm diam.; male zone 3.5–4 cm long, fertile to the apex, pale yellow; stamens crowded, arranged at least in the lower 2/3 of the zone in precise pairs with connate filaments, rectangular from above, 0.8–1 mm across, deeply centrally impressed; thecae on distal and proximal (with respect to spadix axis) sides of the stamen, each with a minute more or less onion-shaped projection (horn) from which the pollen is extruded. Fruiting spathe obconic, c. 2 cm diam.
Distribution
Malesia: Borneo (Sarawak; known only from the vicinity of Matang).
[CATE]

Sources

  • Angiosperm Extinction Risk Predictions v1

    • Angiosperm Threat Predictions
    • http://creativecommons.org/licenses/by/4.0
  • CATE Araceae

    • Haigh, A., Clark, B., Reynolds, L., Mayo, S.J., Croat, T.B., Lay, L., Boyce, P.C., Mora, M., Bogner, J., Sellaro, M., Wong, S.Y., Kostelac, C., Grayum, M.H., Keating, R.C., Ruckert, G., Naylor, M.F. and Hay, A., CATE Araceae, 17 Dec 2011.
    • http://creativecommons.org/licenses/by-nc-sa/3.0
  • Herbarium Catalogue Specimens

    • 'The Herbarium Catalogue, Royal Botanic Gardens, Kew. Published on the Internet http://www.kew.org/herbcat [accessed on Day Month Year]'. Please enter the date on which you consulted the system.
    • Digital Image © Board of Trustees, RBG Kew http://creativecommons.org/licenses/by/3.0/
  • Kew Backbone Distributions

    • The International Plant Names Index and World Checklist of Vascular Plants 2025. Published on the Internet at http://www.ipni.org and https://powo.science.kew.org/
    • © Copyright 2023 World Checklist of Vascular Plants. http://creativecommons.org/licenses/by/3.0
  • Kew Names and Taxonomic Backbone

    • The International Plant Names Index and World Checklist of Vascular Plants 2025. Published on the Internet at http://www.ipni.org and https://powo.science.kew.org/
    • © Copyright 2023 International Plant Names Index and World Checklist of Vascular Plants. http://creativecommons.org/licenses/by/3.0
  • Kew Science Photographs

    • Copyright applied to individual images