Orchidaceae
Polystachya

Polystachya porphyrochila J.Stewart

First published in Amer. Orchid Soc. Bull. 42: 592 (1973)
This species is accepted
The native range of this species is Tanzania (Uluguru Mountains). It is a pseudobulbous epiphyte and grows primarily in the wet tropical biome.

Descriptions

IUCN Red List of Threatened Species https://www.iucnredlist.org/species/179561/1582737

Conservation
CR - critically endangered
[IUCN]

Orchidaceae, V. S. Summerhayes. Flora of Tropical East Africa. 1968

Morphology General Habit
An epiphytic herb, 22–34 cm. high.
Vegetative Multiplication Pseudobulbs
Pseudobulbs from a short rhizome, tightly clustered, narrowly ovoid-conical, slightly compressed, 2.5–5 cm. long, 1.3–2 cm. in diameter, clothed in 3–5 basal sheaths.
Morphology Leaves
Leaf lanceolate to oblanceolate, acute, cuneate below, coriaceous, 22–29 cm. long, 2.5–3.2 cm. broad, articulated 2–3.5 cm. above the pseudobulb apex.
Morphology Reproductive morphology Inflorescences
Inflorescence shorter than the leaf, racemose, 12–20 cm. long, up to 6 flowers borne successively; peduncle stout, 12–16 cm. long; basal sheath membranaceous; bracts spreading, ovate-triangular, acuminate, 8–10 mm. long.
Morphology Reproductive morphology Flowers
Flowers cream with a mauve-purple lip and yellow callus.
Morphology Reproductive morphology Flowers Calyx
Dorsal sepal oblong- ovate, apiculate, 25 mm. long, 8–9 mm. broad; lateral sepals obliquely triangular, falcate, 25 mm. long, 11–18 mm. broad; mentum broadly conical, rounded, 10–17 mm. high.
Morphology Reproductive morphology Flowers Corolla
Petals spreading, elliptic-spathulate, acute, 20 mm. long, 7–9 mm. broad.
Morphology Reproductive morphology Flowers Labellum
Lip strongly recurved in the middle, oblong, 3-lobed in the middle, 30 mm. long, 18 mm. broad, long-pubescent at the base; side lobes elliptic-ovate, papillose; mid-lobe oblong- triangular, shortly apiculate, 15 mm. long, 10 mm. broad; callus fleshy in basal half, obscurely 3-lobed in front.
Morphology Reproductive morphology Flowers Column
Column subterete, winged, 5 mm. long; foot 15 mm. long, pubescent below; pollinia subquadrate-globose.
Habitat
Rain-forest; 1450 m.
Distribution
not known elsewhere T6
[FTEA]

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 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/

  • IUCN Categories

    • IUCN Red List of Threatened Species
    • http://creativecommons.org/licenses/by-nc-sa/3.0

  • Kew Backbone Distributions

    • The International Plant Names Index and World Checklist of Vascular Plants 2024. 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 2024. 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