The orchid flora of Cocos Island National Park ... - Epidendra

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distinguished by the inflorescences having two whitish flowers, > 1 cm in length, the column apex with two teeth in each side and the lateral lobes of lip covering the column apex. The floral features of the three Epidendrum spp. are similar. The only specimen collected for this study seems to be intermediate between E. cocoense and E. insulanum. Basically, the lip shape is similar to E. cocoense, with the same callus structure, but having rounded basal lobes and acute apex as in E. insulanum. The sepals and petals are as long as those of E. cocoense, but the shape is more similar to E. insulanum. Plant size is intermediate between the two species. The column shape also shares intermediate characteristics. The column is oblong as in E. insulanum but with two teeth at apex as in E. cocoense. Trusty (2006) was unable to distinguish this species from E. insulanum. They suggested the possibility that this species could be a hybrid between E. cocoense and E. insulanum and observations of floral morphology support their hypothesis. However, more evidence is needed to complement the morphological data, especially at population genetics and reproductive biology levels. Conservation status: Trusty (2004) suggested classifying this species as CR because of criterion B and D. The estimation of the EOO is < 1km 2 . This species is very rare and restricted to the Wafer Bay areas around the Genio River where it is known from less than five collections. This species has not been evaluated yet under IUCN criteria; however, it should be classified as CR as suggested by Trusty (2004). The endemic Epidendrum species: The three Epidendrum spp. are similar in their vegetative morphology. All the species have a pendent branching habit. The inflorescence is terminal and new branches are produced beneath the apex after they have flowered. The new branches flower again. Flowers are superficially similar. The lip is cordate or subcordate with the callus always Y-shaped. The column has a reduced clinandrium and shows little variation between species. The perianth segments show some variation in size and their shape varies from oblong to ovate–elliptic. Relationships with other members of the genus Epidendrum: According to Hágsater (2007), they are members of the Epidendrum ramosum Jacq. group, which is characterized by the monopodial branching stems, the spike-like distichous inflorescence and the lip with a single callus and the flexicaule subgroup, ORCHID FLORA OF COCOS ISLAND 35 which has a straggling habit, the main stem not very evident and the dorsal keel present in the sepals, which is generally prominent. Epidendrum insulanum is closely related to E. flexicaule Schltr., E. stevensii Hágsater, E. modestiflorum Schltr and E. veraguasense Hágsater (Hágsater, 2007), but they can be distinguished: E. flexicaule has longer leaves (up to 8.2 cm long) and two or three larger flowers, E. stevensii has two or three smaller flowers, E. modestiflorum shorter wider leaves (5 ¥ 15 cm) and two or three flowers and E. veraguasense has two or three white, larger flowers. Epidendrum jimenezii is perhaps closely allied to E. insulanum and E. cocense. Being sympatric and having similar plant size, E. jimenezii and E. insulanum are sometimes confused. Epidendrum cocoense is vegetatively similar to E. rafael-lucasii Hágsater, E. santaclarense Ames and E. acunae Dressler. They are found in Central America and Panama, with the exception of the Costa Rican endemic E. rafael-lucasii. According to Hágsater (1999a), E. rafael-lucasii has larger yellow flowers (vs. white), sepals 16–20 mm long (vs. 12 mm in E. cocoense) and the column is blunt at the apex (vs. with two teeth at each side of apex). Epidendrum santaclarense has deep green flowers (vs. white) and E. acunae has shorter stems and very short flowering stems. Pollination of endemic species of Epidendrum: The pollination biology is unknown. Epidendrum spp. have a deep tube inside the ovary, sometimes with free nectar. The lip and column made up a simple horizontal tube, with the free part of the lip used as an appendage for pollinator attraction. Some species of Lepidoptera, mainly moths, are important pollinators of members of subtribe Laeliinae Benth., including Epidendrum (van der Pijl & Dodson, 1966). The white to whitish flowers of E. cocoense produce a perceptible sweet smell and they could attract some species of moths or butterflies. Nearly 100 species of Lepidoptera are recorded from Cocos Island and moths are the largest group (Brown, Donahue & Miller, 1991; Brown & Miller, 1999). As there are no bees in the island, it is highly probable that the Epidendrum spp. are pollinated by Lepidoptera. Selfpollination was not observed and plants in cultivation flowered without producing fruits. 3. ORNITHIDIUM SALISB. EX R.BR. ORNITHIDIUM SALISB. EX R.BR., Hort. Kew. ed. 2, 5: 210. 1813. Type species: Epidendrum coccineum Jacq., Enum. Syst. Pl. 29. 1760. = Ornithidium coccineum (Jacq.) Salisb., Trans. Hort. Soc. London 1: 293. 1812. EPIPHYTIC, sympodial (caespitose to rhizomatous) or monopodial plants; rarely with dimorphic growth. © 2011 The Linnean Society of London, Botanical Journal of the Linnean Society, 2011, 166, 20–39
36 D. BOGARÍN ET AL. The thick roots with an orangish coloration. STEMS cane-like with distichous leaves or with pseudobulbs bearing basal and apical leaves. The stems and leaves of most species have an olive green coloration. LEAVES conduplicate, coriaceous to subcoriaceous. INFLORES- CENCES usually fascicled, pedicel and ovary longer than the floral bract. FLOWERS usually small, fleshy, campanulate or subglobose, the perianth lacks fibres; many species have yellow, orange, red, tan, green or pink flowers. SEPALS AND PETALS subsimilar, spreading. LIP simple or three- or four-lobed, articulated with or adnate to the column, usually provided at the base with a fleshy callus and often producing nectar at the base of the labellum. COLUMN erect, terete. CAPSULES have apical dehiscence. Ornithidium is a widely distributed genus throughout the Neotropics with approximately 60 species. 1. ORNITHIDIUM ADENDROBIUM (RCHB.F.) M.A.BLANCO &OJEDA, Lankesteriana 7: 532. 2007. Ponera adendrobium Rchb.f., Flora 48: 278. 1865. Pleuranthium adendrobium (Rchb.f.) Benth. & Hook.f. ex B.D.Jacks., Index Kew. 2: 562. 1894. Neourbania adendrobium (Rchb.f.) Fawc. & Rendle, J. Bot. 47: 125 1909. Type: CUBA. 1860–1864, C. H. Wright 1697 (holotype: W; isosintypes: AMES, BM, K, MO). Camaridium parviflorum Fawc. in I. Urban, Symb. Antill. 1: 472. 1900. (Figs 3F, 7). Description: PLANT epiphytic, erect or suberect, with terete, leafy stem, to 60 cm long. ROOTS flexuous, less < 1.5 mm in diameter, orangish to whitish. STEM without pseudobulbs, terete, leafy, covered by addressed leaf sheaths, scarious at base, foliaceous towards the apex, producing secondary branches, with adventitious roots produced at bases of leaf nodes. LEAVES many (to 25), distichous, narrowly oblong to anguste–elliptic, acute, conduplicate, fleshy, flexible, articulate with the sheath involving the stem, to c. 11.0 ¥ 1.6 cm. INFLORESCENCE a singleflowered raceme usually larger than the leaves, produced along the stem, in the axils of the leaves, c. 2 cm long. PEDICEL inconspicuous, < 0.5 mm long. FLORAL BRACTS ovate, foliaceous. OVARY cylindric, < 4 mm long, glabrous. FLOWERS small, inconspicuous, c. 6 mm in length, yellowish to cream–yellow or greenish. DORSAL SEPAL subequal to the lateral sepals, oblong–elliptic, acute or slightly acuminate, 6 ¥ 2 mm. LATERAL SEPALS oblong–elliptic, acute, subfalcate, 6 ¥ 2 mm. PETALS ovate–lanceolate, acute, parallel to the column, 5.0 ¥ 1.7 mm. LIP ovate, lobed, sinuose, retuse, margin erose, callous laminar in the centre, with two parallel keels running to the apex, attached to the column foot. COLUMN short, terete, slightly arcuate, to 3 mm long; stigma ventral, widely obovate, anther terminal. POLLINIA two. ANTHER CAP, cucullate. CAPSULE pyriform to 1.7 cm long. Other vouchers examined: COSTA RICA. Puntarenas: Puntarenas, Isla del Coco, camino al Cerro Iglesias, cerca de Llanos Palo de Hierro, 310 m, 5°31′55.3″N, 87°03′47.8″W, bosque pluvial premontano, transición a basal, epífitas en Sacoglottis holdridgei, 15 abril 2006, D. Bogarín 2755, G. Blanco, G. Gigot, V. Savolainen & J. Warner (JBL-Spirit). Same locality, D. Bogarín 2759 (JBL-Spirit). Puntarenas, Isla del Coco, December 2003, J. Trusty 495 (JBL-Spirit). Same locality: J. Trusty 52 (JBL-Spirit). Isla del Coco: Wafer Bay, 14 august 1973, R.L. Dressler 4470 (CR). Isla del Coco, J. Trusty 52, 100, 157, 495, 515, 556, 564 (CR). december 2003, J. Trusty 52 and 495 (JBL-spirit). Isla del Coco, región de los Llanos y subiendo a Cerro Pelón, 5°32′15″N 87°03′29″W, 200–250 m, 29 junio 1997, A. Rojas 3692 (INB). 6–8 junio 1989, R. Soto s.n. (USJ-49286). Distribution: This is a widespread species ranging from Mexico and the Antilles throughout Central and South America. Etymology: Made up by the Latin prefix ‘a’, ‘away from’ and the name of the genus Dendrobium. According to Reichenbach (1865), the specimen he studied ‘has all characteristics of Dendrobium, therefore the name’. Phenology: The plants have been recorded in flower throughout the year, mostly between September and April Habitat and ecology: Plants are frequent in the island. They are mostly found from 250 to 585 m of elevation, up to the top of Cerro Iglesias. It is rarely found at sea level. Some plants are probably selfpollinated because they form capsules quickly and regularly in almost all flowers. In the field, small ants were observed around the flowers but without pollinia. Capsules are seen throughout the year. Discussion: Plants have distichously arranged leaves without pseudobulbs. Compared with Epidendrum spp., it is easily recognized by the lateral singleflowered inflorescences and the footed column. It is distinguished from C. micranthum by its larger habit, without pseudobulbs and the stem with distichously arranged leaves. The small flowers do not have the lip adnate to the column foot. This species was previously treated in Maxillaria; however, nomenclatural changes in Maxillariinae suggest its inclusion in Ornithidium (Blanco et al., 2007; Whitten et al., 2009). © 2011 The Linnean Society of London, Botanical Journal of the Linnean Society, 2011, 166, 20–39
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The orchid flora of Cocos Island National Park ... - Epidendra

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