Jumellea arachnantha (Rchb. f.) Schltr.

Rakotoarivelo, Fanny, Pailler, Thierry & Faliniaina, Lucien, 2013, Revision of the genus Jumellea Schltr. (Orchidaceae) from the Comoros Archipelago, Adansonia (3) 35 (1), pp. 33-46 : 38-40

2. Jumellea arachnantha (Rchb. f.) Schltr.

( Fig. 4 )

Beihefte zum Botanischen Centralblatt 33 (2): 428 (1915); Perrier de la Bâthie in Humbert H. (éd.), Flore de Madagascar, 49e fam., Orchidées 2: 164 (1941); Stewart et al., Angraecoid orchids: 186 (2006).

— Basionym: Aeranthes arachnanthus Rchb.f. , Flora 68: 539 (1885); Mystacidium arachnanthus (Rchb. f.) T. Durand & Schinz, Conspectus Florae Africae 5: 52 (1895).

— Type: Comoros, Grande Comore, XII.1884, Combani, Humblot 1423 (Lecto-, W! [W-Rchb.Orch. 0011606, “gladiator”], designated here) ; isolecto-, P [ P00090526 , P00090527 , P00090528 ]!).

Jumelllea gladiator (Rchb. f.) Schltr., Beihefte zum Botanischen Centralblatt 33 (2): 429 (1915); Perrier de la Bâthie in Humbert H. (ed.), Flore de Madagascar, 49 e fam., Orchidées 2: 169 (1941); Stewart et al., Angraecoid orchids: 186 (2006). — Basionym: Aeranthes gladiator Rchb.f. , Flora 68: 539 (1885); Mystacidium gladiator (Rchb.) T. Durand & Schinz , Conspectus Florae Africae 5: 53 (1895).

— Lectotype (designated here): Comoros, Grande Comore, Combani, XII.1884, Humblot 1415 (Lecto-, W! [W-Rchb.Orch. 0011607, “arachnantha”] ; isolecto-, P [ P 00090558, P 00090559, P 00090560, P 00090561]!, W [W-Rchb.Orch. 0011606, “arachnantha”]!) . Syn. nov.

Jumellea phalaenophora (Rchb. f.) Schltr. , Beihefte zum Botanischen Centralblatt 33: 430 (1915); Perrier de la Bâthie in Humbert H. (éd.), Flore de Madagascar, 49 e fam., Orchidées 2: 181 (1941); Stewart et al., Angraecoid orchids: 186 (2006).

— Basionym: Aeranthes phalaenophora Rchb.f. , Flora 68: 539 (1885); Mystacidium phalaenophorum (Rchb.f.) T.Durand & Schinz , Conspectus Florae Africae, V, 54 (1892).

— Type: Comoros, s.loc., Humblot s.n. (holo-, W! [W-Rchb. Orch.0011603]) . Syn. nov.

SPECIMENS EXAMINED. — Comoros. Anjouan, Mt. Remani , X.1958, Benson 238 ( BM, P [ P00213132 , P00213133, P00213134]!) ; Dindi forest, Rakotozafy 1091 ( P [P00213138]!). — Grande Comore, Maoueni, La Grille forest, 780 m, 11.XI.1999, Labat et al. 3089 ( P [ P00183938 , P00183939 , P00183940 ]!, BR, CNDRS, G, K, MO) ; Mt. Karthala, XII.1986, Pettersson C12 ( K) ; s.loc., IV.1989, Monnerat s.n. ( P [ P00213137 ]!) ; Hantsangoma, 19.X.2008, Rouhan 740 ( P [ P00684785 ]!) ; Hantsangoma, 19.X.2008, Rouhan et al. 740 ( KM) ; La Grille Massif , Hantsongoma , 11°27’51.8’’S, 43°20’25.4’’E, 1076 m, 27.II.2009, Rakotoarivelo et al. 042 ( REU!) ; Karthala, III.2010, Blambert HB11 (REU!). — Mohéli, Forêt de St Antoine, 1996, Moulaert 0.5 ( P [P00749769]!) ; Oualah II, 12°21’06.4’’S, 43°45’43.6’’E, 401 m, 2.III.2009, Rakotoarivelo et al. 084 ( REU!).

DISTRIBUTION. — Endemic to the Comoros (Grande Comore, Mohéli, and Anjouan), from 400 to 1400 m elevation.

DESCRIPTION

Epiphyte, acaulescent or sub-acaulescent, robust. Leaves large (28-45 × 3-6 cm), oblong, conduplicate at the base, bilobate obtuse at the apex. Peduncle long (7-25 cm), bearing 5 to 6 sterile and tubular bracts at the base, the three first are inserted at the base and the three other distributed irregularly along the peduncle. Inflorescences numerous (2-10). Fertile bract (6-11 mm) tubular, inserted at the base of the pedicellate ovary (4-10 cm). Flower white, the perianth parts of the same size, oblong and acuminate (22-30 × 10-15 mm); lip spathulate (30-45 × 10-15 mm), slightly folded, narrower at the base, widened in the middle, acuminate and carinate at the apex. Spur enlarged, angled, 4-6.5 cm length. Column thin and very short (3 mm long and 2.5 mm in height); lobes of the rostellum acute on the external tips, covered by the anther cap at the upper and joined tips, between which a very small and acute median tongue of the rostellum is visible. Anther cap crested. Capsule fusiform.

REMARKS

Jumellea arachnantha and J. gladiator are very difficult to distinguish from each other ( Stewart et al. 2006). They occur in the same habitat and have the same vegetative and floral aspects. According to Schlechter (1915), both species differ only in their inflorescence lengths. Jumellea arachnanta have a pedicellate ovary longer than the peduncle and the reverse for J. gladiator . However, as we noticed with other Jumellea species, peduncle length is a character which may vary from one plant to another and may increase between two flowering stages. Therefore we consider J. arachnantha and J. gladiator to be conspecific. According to the specimen type and the morphological description by Perrier de la Bâthie (1941), J. phalaenophora is also synonym to J. arachnantha and J. gladiator .

Figures

FIG. 4. — Jumellea arachnantha (Rchb. f.) Schltr.: A, habit; A1, long pedunculate; A2, short pedunculate; B, pieces of the perianth; C, peduncle, pedicellate ovary and spur; D, column, side view. Abbreviations: ms, median sepal; ls, lateral sepals; pt, petals; lp, lip. Scale bars: A, 4 cm; A1, 6 cm; B, C, 1 cm; D, 2 mm.