Epidendrum imthurnii Ridl. 1886 GROUP Elleanthoides SUBGROUP Rhombochilum


Photo by Eric Hagsater/drawing by © R Jimenez and AMO Herbario Website

Common Name Imthurn's Epidendrum [Sir Everard Ferdinand im Thurn (1852-1932), British Orchid Collector, author, explorer, botanist, photographer, and colonial administrator in Guyana]

Flower Size .6" [1.5 cm]

Found in Venezuela, Guyana, Fr. Guiana and Amazonian Brazil on tepui tops or on the slopes at elevations of 2250 to 3000 meters as a medium sized, cold growing terrestrial or lithophyte with erect to slightly curved, terete, thin, few short branched stems produced near the apex of the previous stem and carrying towards the apex or all along the stem, coriaceous, patent, distichous, linear-lanceolate to lanceolate, some slightly falcate; obtuse, slightly attenuate into the base leaves that blooms in the spring on a terminal, without a spathe, racemose, subdense, flowering only once, racemose to paniculate, arching-nutant; peduncle .2 to .38" [5 to 8 mm] long, laterally compressed, thin at the base and gradually widened towards the apex; rachis with 2 to 3 racemes, each raceme ca. .36 to .48" [9 to 12 mm] long, fractiflex, distichous, 1 to 1.6" [2.5 to 4 cm] long, 4 to 8 flowered inflorescence with prominent, as long as the ovary, triangular, acuminate, embracing, divaricate, somewhat recurved floral bracts and carrying resupinate, successive, ochre-yellow to greenish tallow flowerw with the fragrance not registered .

"Epidendrum imthurnii belongs to the GROUP Elleanthoides SUBGROUP Rhombochilum recognized by the branching habit, small fleshy leaves and a short 3 to 6 flowered, nutant inflorescence on a short thick peduncle. The species is recognized by the linear-lanceolate leaves .1 to .172" x .12 to .24" [2.5 to 4.3 x 3 to 6 mm], small ochre-yellow to greenish yellow flowers,sepals .22 to .24" [5.5 to 6.0 mm] long, petals .18 to .22" x .016 to .02" [4.5 to 5.5 x 0.4 to 0.5 mm], linear with the margin entire, and the lip ovate with the apex acute, the angle of the column and the ovary is close to 90°.

Although relatively close to other species of the Elleanthoides Group, several morphological characteristics allow to distinguish it. Epidendrum piconeblinense Hágsater is epiphytic,endemic to the Pico de la Neblina, in the southern tip of Venezuela, bordering on Brazil, the only difference appears to be the narrower, acute petals, and the angle between the column and the axis of the ovary is around 45°; this population is located some 300 km south of Mt. Marahuaca. Epidendrum montigena Ridl. has oblong leaves .8 to 1.4" x .16 to .4" [2 to 3.5 x 0.4 to 1 cm], pink flowers, sepals .26 to .36" [6.5 to 9 mm] long, petals .24 to .32" x .08 to .1" [6 to 8 x 2.0 to 2.5 mm], oblong-elliptic with the margin dentate, and the lip widely rhombic with the apex triangular. Epidendrum alsum Ridl. has ovate leaves 1 to 1.72" x .56 to .72" [2.5 to 4.3 x 1.4-1.8 cm, yellow flowers, sepals 8-9 mm long, petals 7-9 x 1.9 to 2.1 mm], narrowly oblanceolate, the lip 3-lobed. *NOTES: Though the early expeditions to Mt. Roraima state the country of origin as Guyana, they all climbed the tepuí by the only route on foot, on the southwestern side which corresponds to Venezuela. Atop the tepuí, rarely did they venture beyond the immediate vicinity of the point of access. Only those recent collectors who have spent over a week on the summit and arrived by helicopter, can reach the Brazilian and Guyanese sectors. See note by Julian A. Steyermark, 1981. Though Mr im Thurn was sent by Joseph D. Hooker of the British Museum to British Guiana, (and a set remains at BM), scientists at Kew Gardens, identified 53 new species, using the set sent to Kew. (plants.jstor.org/stable/al.ap.person.bm, 2017)" Hagsater etal 2018


References W3 Tropicos, Kew Monocot list , IPNI ; Repert. Spec. Nov. Regni Veg. Beih. 6: 70 Schlechter 1919; Flora de Venezuela Volumen 15 Parte 3 Foldats 1970 drawing ok; Venezuelan Orchids Illustrated Vol 5 Dunsterville & Garay 1972 drawing ok; Orchidaceae Brasilenses Band 2 Pabst & Dungs 1977 drawing good;l Orchids of Venezuela, An Illustrated Field Guide Vol 1 Dunsterville & Garay 1979 drawing ok; Orchids of Venezuela [An illustrated field guide] Vol. 1 Ramiro and Carnevali 2000 drawing ok; AOS Buletin Vol 71 No 5 2002 photo; Flora of the Venezuelan Guayana Vol 7 Steyermark, Berry, Yatskievych and Holst 2003; Orquideas de Roirama Luz & Franco 2012 photo ok; Orchids of French Guiana Szlachetko, Veyret, etal 2012 drawing ok; Orquideas, Tesoro de Colombia Vol 2 Ortiz & Uribe 2017 Drawing good; Icones Orchidacearum 16[1] Plate 1602 Hagsater & Santiago 2018 See recognition section; Icones Orchidacearum 16[1] Plate 1628 Hagsater & Santiago 2018 Drawing/photo fide; Icones Orchidacearum 16[1] Plate 1644 Hagsater & Sanchez 2018 se recognition section; LANKESTERIANA 20(2): 67–216. Ossenbach & Jenny 2020 drawing fide