Acanthaceae
Crossandra

Crossandra sulphurea G.Taylor

First published in J. Bot. 71: 165 (1933)
This species is accepted
The native range of this species is NE. Zambia. It is a perennial or rhizomatous geophyte and grows primarily in the seasonally dry tropical biome.

Descriptions

J. R. Timberlake, E. S. Martins (2013). Flora Zambesiaca, Vol 8 (5) Acanthaceae Part 1. Royal Botanic Gardens, Kew

Type
Zambia, Mbala, 20.vii.1931, Gamwell 56 (BM holotype).
Morphology General Habit
Acaulescent herb from a creeping woody rootstock
Morphology Leaves
Leaves in a rosette, appressed to ground, sericeous or sparsely so, densely so or woolly near base and on petiole, sessile or petiole up to 5 cm long; lamina ovate, elliptic or obovate or narrowly so, largest 11–27 × 3–6 cm, entire or crenate-dentate; apex acute to broadly rounded
Morphology Reproductive morphology Inflorescences
Spike 3–9 cm long; peduncle 0.5–8 cm long, villose
Morphology Reproductive morphology Inflorescences Bracts
Sterile bracts in several pairs, ovate to elliptic, 10–25 mm long, acute to cuspidate, entire, villose; fertile bracts coriaceous, elliptic to spathulate in outline, 18–25 × 10–18 mm, puberulous and pilose, with long capitate glands, also densely ciliate, lower 3-toothed, upper 3-lobed to middle and outer lobes often with additional tooth on outside, lobes ovate, narrowed at base, middle slightly shorter than lateral, acute to acuminate, with a fine pungent mucro, each lobe with a strong central vein and 2 marginal arising from division of basal commissural veins, reticulum raised
Morphology Reproductive morphology Inflorescences Bracteoles
Bracteoles 11–18 mm long, puberulous, pilose-ciliate, with capitate glands
Morphology Reproductive morphology Flowers Calyx
Sepals ovate, cuspidate, sparsely to densely pilose, with long capitate glands, densely ciliate, dorsal 14–20 mm long, ventral 13–18 mm long, lateral 10–13 mm long
Morphology Reproductive morphology Flowers Corolla
Corolla bright lemon yellow, with capitate glands; tube 13–15 mm long, straight; limb 15–22(25) mm long
Morphology Reproductive morphology Flowers Androecium Stamens Anthers
Anthers with connective extended into a small apical peg
Morphology Reproductive morphology Fruits
Capsule (immature) c.9 mm long
Morphology Reproductive morphology Seeds
Seeds not seen.
Distribution
Zambia. Not known elsewhere.
Ecology
Brachystegia woodland on sandy soil; 750–1700 m.
Conservation
Endemic to NE Zambia; not threatened.
Recognition
Crossandra sulphurea is known only from a small area around Mbala but has been collected almost up to the Tanzanian border and probably also occurs in SW Tanzania. The deeply 3-lobed bracts clearly show that its closest relatives are C. tridentata and C. friesiorum, two white-flowered species from Kenya and Tanzania.
[FZ]

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]

Sources

  • Angiosperm Extinction Risk Predictions v1

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

  • Flora Zambesiaca

    • Flora Zambesiaca
    • 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 2026. 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 2026. 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