Habenaria armatissima Rchb.f., Otia Bot. Hamburg.: 98 (1881).
Homotypic Synonyms:
Arachnaria armatissima (Rchb.f.) Szlach., Richardiana 3: 156 (2003).
Heterotypic Synonyms:
Habenaria eburnea Ridl., J. Bot. 24: 293 (1886).
Habenaria lugardiae Rolfe in D.Oliver & auct. suc. (eds.), Fl. Trop. Afr. 7: 228 (1898).
Habenaria dinteriana Kraenzl., Vierteljahrsschr. Naturf. Ges. Zürich 74: 106 (1929).
Description:
A terrestrial herb 3-7 dm. high, glabrous except for the roots. Tubers ellipsoid or elongate-ovoid, 2.5-1.5 cm. long, 1-2.5 cm. in diameter, densely tomentose. Stem erect, rather stout, with 2 large leaves at the base and several much smaller ones along its length. Basal leaves opposite, adpressed to the ground, broadly ovate to reniform, apiculate to rounded, often somewhat cordate at the base, 6-18 cm. long, 7-22 cm. broad, rather fleshy; cauline leaves 4-8, ± adpressed to stem, lanceolate, acuminate, up to 5 cm. long. Inflorescence 10-20 cm. long, 8-12 cm. in diameter, closely 10- to many-flowered. Bracts lanceolate, acuminate, similar to the cauline leaves, 1-3.5 cm. long, distinctly shorter than the pedicel with ovary. Flowers ± spreading, white; pedicel with ovary often slightly curved, 3-5.5 cm. long. Dorsal sepal erect, elliptical-ovate, acuminate, very convex, 11.5-16 mm. long, 5-8 mm. broad; laterals reflexed, very obliquely semi-orbicular or semi-ovate, acuminate, 13-17.5 mm. long, 4-7.5 mm. broad. Petals bipartite nearly to the base; posterior (upper) lobe erect, curved-linear, 11.5-14.5 mm. long, scarcely 1 mm. broad; anterior lobe projecting forwards or spreading, almost filiform, 3-4 cm. long, about as broad as the posterior in the lower part. Lip projecting forwards, tripartite from an undivided base ± 2 mm. long; all lobes linear or nearly filiform, 0.5-1 mm. broad, the middle lobe 1.5-2 cm. long, the side lobes 3-4.5 cm. long; spur dependent, narrowly cylindrical, hardly swollen in the apical part, 8.5-21.5 cm. long. Anther erect, apiculate, 6-9 mm. high, canals curved upwards, 3.5-5 mm. long; stigmas porrect or slightly decurved, club-shaped from a very slender base, truncate, 5.5-10 mm. long, rostellum narrowly triangular, acute, 4-6 mm. high.
Habitat:
Forests, open marshy ground, grasslands and dry deciduous, and mixed woodlands often on termite mounds. Up to 1550 m.
Phenology:
Flowering throughout the year.
Notes:
This species appears to be related to Habenaria subarmata but not as in the latter species it has dorsal sepal 11-16 mm long, and spur 5-205 mm long. In Habenaria subarmata the dorsal sepal is 7-11 mm long and spur 50-75 mm long.
Cultivation:
As given for the genus, hot to cool growing terrestrial.
Distribution:
Mali, Nigeria, Chad, Zaire, Cameroon, Eritrea, Ethiopia, Sudan, Kenya, Tanzania, Malawi, Zambia, Zimbabwe, Mozambique, Botswana and Namibia.
References:
Orchidaceae of West-central Africa, vol. 1, Gdansk University Press Gdansk 2010; The Orchids of South Central Africa Williamson 1977; Orchids of Kenya Stewart & Campbell 1996; Field Guide to Ethiopian Orchids Demissew, Cribb and Rasmussen 2004; Terrestrial African Orchids, A select Review John S. Ball 2009; African Orchids: IV V. S. Summerhayes, Bulletin of Miscellaneous Information (Royal Gardens, Kew), Vol. 1932, No. 7 (1932), pp. 338-344; New Species of Habenaria (Orchidaceae) from Ethiopia S. Thomas, Kew Bulletin, Vol. 51, No. 1 (1996), pp. 145-154
Images:
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Photograph© Claude Boucher Chisale. Image used with kind permission from African plants – A Photo Guide. www.africanplants. senckenberg.de	Photograph© Claude Boucher Chisale. Image used with kind permission from African plants – A Photo Guide. www.africanplants. senckenberg.de	Photograph© Claude Boucher Chisale. Image used with kind permission from African plants – A Photo Guide. www.africanplants. senckenberg.de	Photograph© Claude Boucher Chisale. Image used with kind permission from African plants – A Photo Guide. www.africanplants. senckenberg.de	Photograph© Claude Boucher Chisale. Image used with kind permission from African plants – A Photo Guide. www.africanplants. senckenberg.de	Photograph© Claude Boucher Chisale. Image used with kind permission from African plants – A Photo Guide. www.africanplants. senckenberg.de	Photograph© Claude Boucher Chisale. Image used with kind permission from African plants – A Photo Guide. www.africanplants. senckenberg.de	Photograph© Claude Boucher Chisale. Image used with kind permission from African plants – A Photo Guide. www.africanplants. senckenberg.de