Epidendrum posticorevolutum Hagsater, Cisneros & Edquen 2020 GROUP Arbuscula SUBGROUP Incomptum

LCDP Photo by © J. D. Edquén & A. Cisneros and Icones Orchidacearum 18(1) plate 1832 2020

Common Name The Rolled Back Epidendrum [refers to the posterior margin of the lip which is rolled down]

Flower Size .8" [2 cm]

Found in Amazonas department of Peru on the eastern slope of the Andes at elevations around 3150 meters as a small sized, cold growing sympodial epiphyte with , erect, simple, cane-like, thin, terete, straight, progressively larger stems covered by several nonfoliar sheaths and carrying 2 to 3, aggregate at the apex of the stems, alternate, suberect, somewhat conduplicate at the base, blade sub-equal, narrowly elliptic, acute, dark green above, somewhat paler on the underside leaves that blooms in the winter on a terminal, without a spathe, peduncle 1.2" [3 cm] long, slightly laterally compressed, not ancipitose, rachis 1.28 to 1.4" [3.1 to 3.5 cm] long, racemose, arching, nutant, successively, eventually all open at once, to 7 flowered inflorescence with decreasing, triangular-lanceolate, acute, embracing, much shorter than the ovary floral bracts and carrying resupinate, fleshy flowers.

"Epidendrum posticorevolutum belongs to the GROUP Arbuscula SUBGROUP Incomptum, which is characterized by the erect habit with successive lateral growths being produced from the middle of the previous growth, the few leaves aggregate towards the apex of the stems, roots are produced generally only from the base of the primordial stem, the inflorescences are short with fleshy yellowish to green to violet-green to black flowers with short ovaries, and the lip is entire to 3-lobed. The species is recognized by the olive-green flowers, somewhat tinged brown, the column and disc of the lip pale green, the short ovary, .4 to .52" [10 to 13 mm] long, the oblanceolate petals .48 x .12" [12 x 3.0 mm], and the 3-lobed lip, with obovate lateral lobes, apically sub-truncate, .512 to .56" [12.8 to 14 mm] long, the apices aligned with apex of the mid-lobe, the laminar calli, each forming a low, thin rib that disappears before the apices of the lobes lobe of the mid-lobe. Epidendrum rimarachinii Hágsater has a many-flowered inflorescence, an elliptic, 6-veined dorsal sepal, a 3-lobed lip, the sides strongly revolute and thus apron-like, the mid-lobe shorter, about .1" [2.5 mm] long, bicallose, calli redounded, somewhat laterally compressed, the disk with 3 mid ribs, and a longer column, about .44" [11 mm] long. Epidendrum ulcumanoae Hágsater, G.Gerlach & L.Valenz. has sepals and petals olive green to yellow tinged somewhat brown, lip and calli pale yellowish green, with long, apiculate sepals .72 to .76" x .256 to .36" [18 to 19 x 6.4 to 9.0 mm], falcate, oblanceolate petals .52 to .6" x .216" [14 to 15 x 5.4 mm], and the obreniform lip .56 x 1" [14.5 x 25 mm], widest at the middle, the lateral lobes semi-orbicular, with a slightly receded mid-lobe, itself formed by a pair of semi-orbicular lobules, the lip with the lateral margins revolute so as to appear apron like in natural position. Epidendrum chisquillense Hágsater, Edquén & Cisneros similar, but larger plants, with flowers green concolor, larger ovary .76" [19 mm] long), sepals larger .66 to .676" [16.5 TO 16.9 mm] long, with margin revolute in natural position, elliptic to oblique oblanceolate, somewhat falcate, smaller lip .38 x .746" [9.5 x 18.6 mm], 2-lobed, obreniform in general outline and a longer column .44" [11 mm] long." Hagsater & Cisneros 2020


References W3 Tropicos, Kew Monocot list , IPNI ; Icones Orchidacearum 18(1) plate 1806 2020 see recognition section * Icones Orchidacearum 18(1) plate 1832 Hagsater, Pfahl & Cisneros 2020 photos fide; Icones Orchidacearum 18(1) plate 1844 Hagsater & Santiago 2020 see recognition section