Polystachya songaniensis G. Will. [family ORCHIDACEAE]

Herbarium
Royal Botanic Gardens, Kew (K)
Collection
Flora Zambesiaca
Resource Type
Reference Sources
Entry From
FZ, Vol 11, Part 2, (1998) Author: I. la Croix & P.J. Cribb
Names
Polystachya songaniensis G. Will. [family ORCHIDACEAE], in Orchid Rev. 90: 128 (1982). —la Croix et al., Orch. Malawi: 220 (1991). TAB. 110. Type: Malawi, Zomba Mt., Oct. 1980, Gassner 115 (K, holotype).
Information
Small, epiphytic or lithophytic herb, forming dense mats, flowering when leafless.Pseudobulbs 10–15 × 10–13 mm, squat, onion-shaped, shiny green or purplish, wrinkled when old, 2–3-leaved.Roots long, stout, to 4 mm in diameter.Leaves up to 15 × 0.5 cm, linear, grass-like.Inflorescence (floral axis) 3–15(35) cm tall; rhachis short, 1–2 cm long, with a few short branches, densely many-flowered.Flowers pale to deep pink, occasionally white, the lip with a large oblong bright yellow callus in the centre.Pedicel and ovary 4–5 mm long, slender, purple.Dorsal sepal c. 2.5 × 1.3 mm, ovate, obtuse; lateral sepals c. 4 × 1.6 mm, ovate, forming with the column foot a narrow, cylindrical mentum c. 2 mm long.Petals c. 3 × 1.2 mm, spathulate.Lip entire, 3.8–5 × 1.5–3.5 mm, obovate, frilly-edged, with a large, oblong, rugulose callus in the centre.Column 1–1.5 mm long.
Habitat
On mossy tree trunks, rocks and sedge clumps, also on exposed wet rock of seepage slopes, often forming dense mats up to c. 30 cm in diameter
Range
Endemic to Zomba and Mulanje Mountains
Altitude range
1200–2450 m.
2450
1200
Distribution
Malawi S Zomba Mt., Songani Lookout, c. 1900 m, fl. x.1980, Gassner 115 (K); Zomba Mt., 1800 m, fl. 26.x.1980, la Croix 22 (K); Mulanje Mt., Lichenya Plateau, Nessa Path, 1800 m, fl. 15.xii.1988, J.D. & E.G. Chapman 9437 (K; MO).
Notes
Plants from Mulanje Mt. can have much taller inflorescences, sometimes up to 35 cm, but are otherwise the same as the Zomba plants.Williamson, in his protologue, placed this odd but attractive little species in section Eurychilae, near P. greatrexii Summerh., but it fits much better into section Elasticae, a predominantly West African section, but with another representative in the Flora Zambesiaca area in P. saccata.
Polystachya songaniensis G. Will. [family ORCHIDACEAE]
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