Acanthaceae
Crossandra

Crossandra stenostachya (Lindau) C.B.Clarke

First published in D.Oliver & auct. suc. (eds.), Fl. Trop. Afr. 5: 113 (1899)
This species is accepted
The native range of this species is Ethiopia to NE. Tanzania. It is an annual and grows primarily in the seasonally dry tropical biome.

Descriptions

Acanthaceae (part 2), Kaj Vollesen. Flora of Tropical East Africa. 2008

Type
Type: Kenya, Machakos/Kitui District: Ukamba, Hildebrandt 2720 (B†, holo.; COR, iso.; K!, fragment & photo).
Morphology General Habit
Erect annual herb to 35 cm tall, unbranched with an apical rosette of leaves and 1–4 sessile spikes or with up to 4 branches up to 10 cm long from the rosette and these each ending in a rosette with a single sessile spike; young stems glandularpuberulous to pilose. Leaves subsessile; lamina obovate or narrowly so, largest 5–15 × 1–5 cm, apex subacute to broadly rounded, pubescent or sparsely so, usually only on veins when mature
Morphology Reproductive morphology Inflorescences
Spikes 2–12 cm long; fertile bracts broadly obovate to orbicular or transversely elliptic, 12–16 × 10–17 mm, ending in a straight spine 2–6 mm long and on each side with 4–6 prickles 3–6 mm long (sometimes also with a few short ones between these), basal part pilose, apical part puberulous, venation reticulate, very prominently raised; bracteoles 11–14 mm long, pilose
Morphology Reproductive morphology Flowers Calyx
Sepals lanceolate with long cuspidate-spinulose tip, pilose near tip, dorsal 12–15 mm long, ventral 10–13 mm long, lateral 9–11 mm long
Morphology Reproductive morphology Flowers Corolla
Corolla bright yellow; tube up to 15 mm long; limb 8–13 mm long
Morphology Reproductive morphology Flowers Androecium Stamens Anthers
Anthers with a small apical horn
Morphology Reproductive morphology Fruits
Capsule 8–10 mm long
Morphology Reproductive morphology Seeds
Seed 3–4 × 2.5–3 mm.
Ecology
Grassland and Acacia bushland on black cotton soil, wet depressions in Acacia-Commiphora bushland, riverine forest and riverbanks; (150–)300–1200 m
Note
The pollen grains of this species are the longest ever reported in terrestrial angiosperms. They are rod-shaped and ± 0.5 mm long (visible with the naked eye). See Brummitt, Ferguson & Poole in Pollen et Spores 22: 12 (1980). They are probably a rudiment of the second locule. The peculiar small apical horns on the anthers have not been seen in any other species.
Distribution
Flora districts: U1 K1 K3 K4 K6 K7 T3 Range: Ethiopia, Somalia
[FTEA]

M. Thulin et al. Flora of Somalia, Vol. 1-4 [updated 2008] https://plants.jstor.org/collection/FLOS

Morphology General Habit
Annual herb, 5–30 cm tall; young branches glandular hairy
Morphology Leaves
Leaves seemingly in whorls of 4, pubescent, subsessile; blade oblong-elliptic, 2–12 x 1–5 cm, subacute to obtuse at the apex
Morphology Reproductive morphology Inflorescences
Spikes sessile, 3–10 cm long; bracts with spiny tip and spiny margins, broadly obovate, c. 12 x 10 mm excluding spines, ± sparsely pilose, with 5–7 strong longitudinal veins and raised reticulum
Morphology Reproductive morphology Flowers Corolla
Corolla yellow; tube c. 15 mm long; limb c. 12 mm long.
Distribution
S1, 3; Ethiopia, Uganda, Kenya, Tanzania
Ecology
Altitude range 50–200 m.
[FSOM]

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: not threatened. Confidence: confident
[AERP]

Sources

  • Angiosperm Extinction Risk Predictions v1

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

  • Flora of Somalia

    • Flora of Somalia
    • http://creativecommons.org/licenses/by-nc-sa/3.0

  • Flora of Tropical East Africa

    • Flora of Tropical East Africa
    • 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