Cynorkis mammuthus Hermans & P.J.Cribb, Kew Bull. 72(3)-38: 13 (2017).
Description:
Plant tubers, roots and foliage not known. Inflorescence total length not known, c. 3 mm in diam.; rachis c. 15 cm, densely racemose with up to 11 flowers; floral bracts funnel-shaped, serrate-hirsute at the margin, acuminate, then apiculate at the apex, about 1 3 the length of the pedicellate ovary 21 - 25 mm long, 8 - 10 mm wide; pedicel and ovary densely hirsute, almost straight, 60 - 68 mm long, 1.8 - 2.1 mm wide. Flowers overall c. 4 - 5 cm long, 2.5 - 3.5 cm wide, not including the spur. Dorsal sepal 32 - 34 mm long 14 - 16 mm wide when flattened, forming a hood with the petals, gibbose, expanded and hirsute at the base; lateral sepals spreading, oblong-elliptic with a distinctive wing on the upper margin towards the tip, 29 - 30 mm long, 12 - 13 mm wide. Petals appressed to the inside of the dorsal sepal margins, linear-lanceolate, 31 - 33 mm long, 2.5 - 2.8 mm wide. Lip entire, oblanceolate, naviculate, acuminate at the tip, 36 - 38 mm long, 12 - 14 mm wide; spur down-curved then pendent, subulate, 10.5 - 13 cm long, c. 2 mm in diam. Column in an angular plane 33 - 35 mm long 9 - 11 mm wide, with two very long rostellum arms for more than half its length, a small nose-like mid-lobe, staminodes towards the base, forming triangular auricles, anther loculi ovate, pollinia including the long caudicle c. 28 mm long.
Etymology:
The species name refers to the likeness of the profile of the flower to the head of a mammoth with the rostellum arms as tusks and long trunk-like spur. It is also larger than its nearest relative Cynorkis elephantina, possibly extinct in the wild and only known from dried specimens.
Habitat:
Not known.
Notes:
The new species is distinct by the raceme of very large flowers for the genus, up to 11 on the raceme, densely hirsute pedicellate ovary and base of flower, the entire lip with a very long pendent spur, lateral sepals with an auricle towards the apical margin and the very long tusk-like rostellum arms. It could be perceived as a peloric form of Cynorkis christae but the longer rostellum arms, lobed lateral sepals and 8- to 11-flowered inflorescence (vs 3 - 4 in C Cynorkis christae) make it unlikely. It shares its large flower size with Cynorkis gigas Schltr. (Schlechter 1924: 50) but has an 8 - 12-flowered inflorescence, an entire vs a distinctly lobed lip, clearly lobed lateral sepals and a longer spur (c. 10 cm in Cynorkis gigas vs 13 cm in the new species). The large flower and long spur are reminiscent of Cynorkis christae Hermans, Andriant. & Sieder described above, which comes from the same area in Madagascar, but differs in its lip and lateral sepals. In flower morphology the new species is closest to Cynorkis elephantina Hermans, Andriant. & Sieder described above, with which it shares the entire lip, the densely hirsute pedicellate ovary, lobed lateral sepals and long rostellum but its sepals and petals are about twice as large, its lip and spur almost a third larger, its floral bracts broad and funnel-shaped (vs shortly amplexicaul in Cynorkis elephantina), its hood, formed by the dorsal sepal and petals, is not recurved, its rostellar arms are longer and its spur is up to 13 cm long (vs 7.8 cm).
This enigmatic new species is known from two dried inflorescences only; the first from a herbarium sheet of flowers collected in 1994 as Cynorkis uniflora Lindl. (Lindley 1835: 331) by a Malagasy orchid nursery and a second collection from 1942 in the Paris Herbarium (P), last seen about 10 years ago and currently only known from a photographic record. The latter specimen, originally from the ‘Herbier du Jardin Botanique Tananarivo Madagascar’, was identified as Cynorkis gigas Schltr. but annotated by Jean Bosser as ‘not Cynorkis gigas, nothing to do with this species’.
Cultivation:
As given for the genus.
Distribution:
Only known from the Antsohihy area I Northern Madagascar.
References:
New species and nomenclatural changes in Cynorkis (Orchidaceae: Orchidoideae) from Madagascar and the Mascarenes, KEW BULLETIN (2017) 72: 38
