Kylicanthe quintasii (Rolfe) Farminhão, Stévart & Droissart 2018

Descourvières, Pascal, Farminhão, João N. M., Dubuisson, Vincent Droissart Jean-Yves, Simo-Droissart, Murielle & Stévart, Tariq, 2018, A new genus of angraecoid orchids (Orchidaceae: Angraecinae) with highly distinctive pollinaria morphology, including three new species from tropical West and Central Africa, Phytotaxa 373 (2), pp. 99-120 : 113-114

Kylicanthe quintasii (Rolfe) Farminhão, Stévart & Droissart , comb. nov. ( Fig. 2E )

Basionym:— Angraecum quintasii Rolfe (1891: 140) . Type:— SÃO TOMÉ AND PRÍNCIPE. São Tomé: 1,200 m, October 1888, Quintas

6 (lectotype, designated here: K! [K000306248]; isolectotypes: BM! [BM000529317], COI! [COI00072626]). Homotypic synonyms:— Diaphananthe quintasii (Rolfe) Schlechter (1918: 99) , Mystacidium quintasii (Rolfe) Rice (2006: 13) . Heterotypic synonyms:— Diaphananthe alfredii Geerinck (1990: 182) . Type:— BURUNDI. Muramvya: Teza, S03°13’, E29°33’, 2,100 m,

13 December 1979, Reekmans 8464 (holotype: BR! [BR0000008809629]; isotype K! [K000306247]). Rhipidoglossum magnicalcar Szlachetko & Olszewski (2001: 860) . Angraecopsis magnicalcar (Szlach. & Olszewski) Rice (2005:19) .

Type:— GABON. Belinga, bord de piste, 500 m, s.d., Moungazi 230 (holotype: P! [P04026599]).

Epiphytic herbs. Roots numerous, basal on the stem, unbranched, greyish, 2–4 mm in diameter. Stem up to 55 mm long, 3–10 mm in diameter, unbranched, pendent to erect, internodes 2–5 mm. Leaves distichous, less than 10, narrowly obovate to narrowly elliptic sometimes falcate, tessellated, subcoriaceous, margins entire, apex unequally bilobate, most often with a distinctive notch, lobes obtuse to acute, 50.0–160.0 × 7.5–27.0 mm. Inflorescences usually 1 to 3, semi–pendent, emerging at the base of the stem, with up to 20 flowers, 30–300 mm long, floral internodes about 3–15 mm, rachis terete; bracts amplexicaul, 2–6 mm long. Flowers resupinate, cream to greenish–orange turning yellowish orange to orange in late anthesis, 7–11 mm in diameter; dorsal sepal elliptic, sometimes obovate, apex obtuse to subacute, margins entire, 3.0–4.3 × 2.0– 2.5 mm; lateral sepals obliquely elliptic, sublinear to linear, slightly keeled dorsally, apex obtuse to subacute, margins entire, 1–5-veined, 3.2–4.6 × 1.2–2.0 mm; angle between dorsal and lateral sepals about 120° but then with a torsion that places it at 180 ° to the dorsal sepal; petals elliptic linear, apex obtuse to subacute, margins entire, 2.8–4.0 × 1.0–2.0 mm; lip ovate, margins entire, laterally compressed, bearing a callus, apex generally subacute, sometimes with a little notch, 3–7-veined, 2.5–4.0 × 2.0– 3.5 mm; lip callus, a small obtuse tooth in the mouth of the spur; spur more or less curved, downward projecting, roughly circular in cross section to dorsoventrally flattened, mouth slightly spreading, apex obscurely inflated, proximal part of the spur approximately parallel to the ovary, 6–11 mm long; ovary and pedicel 4.0–6.0(8.0) × 0.8–1.5 mm. Column 2.0–3.0 × 1.5–2.5 mm; anther cavity approximately perpendicular to the axis of the column; stigmatic cavity cup-shaped, margins winged, 3 veins; rostellum triangular and bifid, about 1 mm long; pollinia 2, spherical; stipes 2, spatulate, connate along the apical third of their length, with a bulging outer margin, fringed, 1.0– 1.6 mm long, connected to a single calceiform viscidium. Fruits ventricose, pedicellate.

Distribution: —Widespread in Central Africa, from São Tomé, Cameroon and Gabon east to the Albertine Rift, reaching western Uganda, also in Angola, up to 2,000 m ( Fig. 3 ).

Habitat and ecology: —Epiphytic in primary and secondary forest and plantations (e.g. coffee, avocado).

Phenology: —Flowering September–April.

Conservation status: —The IUCN Red List category is near threatened [NT]. The extent of occurrence (EOO) of K. quintasii is estimated to be 3,061,937 km 2, which falls above the limits for vulnerable category under criterion B1, and its area of occupancy (AOO) is about 80 km 2, which falls within the limits for endangered category under criterion B2. It is known from ten subpopulations in Central Africa, four of them occurring in protected areas. These 10 subpopulations represent 11 locations (sensu IUCN 2012), which fall just above the limits for the vulnerable category. However, the habitat of K. quintasii currently appears to be threatened in most of its distribution, the species occurring in dense humid forests, outside national parks, where there is no protection. Its survival in these areas could become threatened within the next ten years by shifting agriculture, selective logging and/or small-scale subsistence forest exploitation, a situation that justifies a preliminary risk of extinction assessment of NT.

Etymology: —The species epithet honours Francisco Joaquim Dias Quintas, who collected the type. He was a plant collector who made an important contribution to the study of the flora of São Tomé, working there as a correspondent of Júlio Henriques from the University of Coimbra ( Carrisso 1934).

Notes: —This is the species identified as Diaphananthe rohrii in the molecular phylogenetic study of Simo-Droissart et al. (2018). Kylicanthe quintasii is polymorphic in leaf and lip spur shape. Leaves vary greatly from almost linear to oblanceolate, but no geographical pattern can apparently be related to this variation. On the contrary, regarding spur morphology, there are geographically related differences in shape and length among different localities, with plants from São Tomé (including the type specimens) presenting a much more dorsoventrally flattened, curved and often much shorter spur than plants from the mainland. Kylicanthe quintasii (as Diaphananthe quintasii ) was put in synonymy of Diaphananthe rohrii by Cribb (1989). However, both taxa can easily be distinguished by their divergent floral traits and apparently present non-overlapping distributions: K. quintasii occurs in Central Africa reaching western Uganda to the east and has cream, orange or yellowish-orange flowers with an inconspicuous lip callus at the entrance of the spur, whereas K. rohriii , confined to East Africa but reaching eastern Uganda to the west, has green to yellowish green flowers with a prominent lip callus at the entrance of the spur. Diaphananthe alfredii , regarded as a synonym of D. rohrii by Fischer et al. (2010), falls well within the variation of K. quintasii and refers to the plants from the Albertine Rift. Additionally, Rhipidoglossum magnicalcar , only known from the type from Gabon (Moungazi 230) deposited at P, is here first reported as a synonym of K. quintasii , agreeing well with the type from São Tomé Island and with material from Angola, Cameroon and the Albertine Rift. The only known records of D. quintasii / D. rohrii for the Central African Republic to which Govaerts et al. (2018) probably made reference, Harris & Fay 106 (P, MO), in addition to two specimens that have been cited for the Democratic Republic of the Congo, Évrard 4886 & 5096 (BR) by Geerinck (1992: 564), do clearly not correspond to K. quintasii . Actually, all these specimens agree well with D. plehniana (Schltr.) Schlechter (1918: 97) and represent a new addition to the flora of these two countries. Geerinck (1992) cited two other specimens of D. rohrii for the DRC, Évrard 4771 and Évrard 4049, but these correspond to undetermined species of Diaphananthe or Rhipidoglossum . Finally, an additional fruiting specimen from Angola (Gossweiler 10129) housed at COI may correspond to K. quintasii .

Additional specimens examined: — SÃO TOMÉ AND PRÍNCIPE. São Tomé: São Nicolau, 12 September 1912, Watt 7332 (K) ; Parque Nacional Obô , plantation d’avocatiers, 830 m, 0°17’30’’N 6°36’45’’E, 2 October 1998, Stévart & Oliveira 207 (BRLU, K) ; Estação Sousa , 1,700 m, 0°15’N 06°33’E, 2 September 1997, Stévart 100 (BRLU) ; entre Mesa et Morro Vilela , 1,700 m, 0°17’ N, 6° 33 E ‘, Stévart 130 (BRLU) ; near Morro Vilela , 1,167 m, 0°17’N, 6°33’E, 24 February 2008, Oliveira 1279bis (BRLU!) ; Morro Vilela, 1,054 m, 20 September 2008, Oliveira 1518 (BRLU) ; ibid. loc., 24 October 2012, Bom Sucesso shadehouse series 483 (BRLU) ; ibid. loc., 816–977 m, 25 October 2012, Stévart, & Droissart 4708 & 4709 (BRLU, MO, P, WAG) ; Pico Grande (Pico de São Tomé), 0°16.15’N 6°32.80’ E, 10 October 2009, Bom Sucesso shadehouse series 433 (BRLU) ; caminho de Macambrara, 1,380 m, 17 January 2008, Oliveira 1514 (BRLU!) ; entre Bom Sucesso et Zampalma – Macambara , 0°16’N 06°36’E, 30 September 1997, Stévart 183 (BRLU) ; Bom Sucesso vers Lagoa Amélia (sentier S.P, km 0,6), 1,300 m, 4 October 1997, Lejoly 97-363 (BRLU) ; ibid. loc., 2 October 1998, Stévart 215 (BRLU!) ; Lagoa Amélia , 1,430 m, 0°17’00”N 6°35’30”E, 4 July 1998, Stévart 383 (BRLU!) ; ibid. loc., 2 October 2009, Bom Sucesso shadehouse series 418 (BRLU) ; above Zampalma, 750–850 m, 22 March 1998, Brune ST69 (K) ; Nova Ceilão , 0°16’30”N 6°35’30”E, 1 November 1998, Stévart 494 (BRLU, K) . CAMEROON. Centre: Mbam-Minkom (région de, au NO de Yaoundé ): inselberg et forêt sommitale, est/sud-est du village de Nkolakié , 900 m, 3°58’10.38”N 11°23’43.74”E, 13 September 2004, Yaoundé shadehouse series 114 (BRLU, YA) ; ibid loc., 31 August 2006, Yaoundé shadehouse series 424 (BRLU) ; ibid. loc., Yaoundé shadehouse series 662 (BRLU) ; ibid. loc., 29 September 2009, Yaoundé shadehouse series 1817 (BRLU) ; ibid. loc., 17 September 2010, Yaoundé shadehouse series 2385 (BRLU) ; Village de Nye-Meyong: à 900 m du campement vers le village Ekekam, 865 m, 3°54’58.10”N 11°22’34.54”E, 7 September 2008, Yaoundé shadehouse series 1282 (BRLU, YA). Mt Ngoro , entrée via le village de Nyadingi , 1,100 –1,300 m, 5° 5’50.82”N 11°19’46.16”E, 27 August 2012, Yaoundé shadehouse series 3774 (BRLU, YA) ; Ouest: Monastère de Koutaba, entre Bafoussam et Foumban, 1,164 m, 5°38’51.65”N 10°48’22.39”E, 21 August 2014, Yaoundé shadehouse series 5434 (BRLU) ; ibid. loc., 10 August 2015, Yaoundé shadehouse series 6281 (YA) ; ibid. loc., 23 August 2015, Yaoundé shadehouse series 6855 (WAG) . ANGOLA. Cazengo: 1903, Gossweiler 733 (BM, K, P). DEMOCRATIC REPUBLIC OF THE CONGO. Langa: 7 February 1974, s. col. s.n. (BRLU) . UGANDA. Western Region: Bwamba pass, Toro, 2,440 m, 13 August 1938, Thomas 2358 (K). Budongo Forest , 22 April 1968, Leakey s.n. (K) . RWANDA. Western: Cyamudongo Forest , 2,004 m, 2°33’31.74”S 28°58’59.10”E, 30 January 2018, Farminhão & Dumbo 245 (BRLU) . BURUNDI. Rutana: Buruririv., Siguvyaye , 03°57’ S, 29°56’ E, 30 January 1992, Arbonnier 304 (BR) .

Figures

FIGURE 2. Overview of Kylicanthe diversity. A. Kylicanthe arcuata, plants growing as twig epiphytes in Mt. Etindé (Cameroon) and detail of the flowers. B. Kylicanthe perezverae, seed capsules of a plant grown at the Nimba shadehouse (Guinea). C. Kylicanthe liae, habit and detail of a flower showing a prominent orange viscidium, in cultivation at Huye orchid garden of the University of Koblenz- Landau guest house (Rwanda). D. Kylicanthe bueae, habit of a plant grown at Yaoundé shadehouse (Cameroon) and detail of a flower. E. Kylicanthe quintasii, detail of inflorescence of a plant from São Tomé Island. F. Kylicanthe rohrii, detail of inflorescence of a plant from Tanzania. G. Kylicanthe cornuata, detail of flowers of a plant grown at Yaoundé shadehouse (Cameroon). Photographs by: A., D. and G. Vincent Droissart; B. Ehoarn Bidault; C. Eberhard Fischer; E. Tariq Stévart; F. W. Bachmann, facilitated by the World Orchid Iconography of the Swiss Orchid Foundation at the Herbarium Jany Renz (Botanical Institute, University of Basel, Switzerland).

FIGURE 3. Distribution of the seven species of Kylicanthe in tropical Africa.