Epidendrum retrolobatum Hágsater, Chamaya, J.Duarte & Iberico, 2023

Gonzáles, James Alexander Chamaya, Hágsater, Eric, Ayala, Elizabeth Santiago, Salinas, Julian Duarte & Vela, Gustavo Iberico, 2023, Three new species of Epidendrum (Orchidaceae: Laeliinae) from the cloud forests of Chota, northern Peru, Phytotaxa 625 (1), pp. 77-87 : 81-83

Epidendrum retrolobatum Hágsater, Chamaya, J.Duarte & Iberico , sp. nov. ( Figures 1 , 3 )

Type: — PERU: Cajamarca: Prov. Chota: Distr. Chota : comunidad La Palma , 200 metros de la laguna El Corazón , 2976 m, 25 enero 2023, J. A. Chamaya G. 111 (holotype: CPUN!) .

Epidendrum retrolobatum is similar to Epiendrum ferreyrae Hágsater & Ric.Fernández (2007: t. 936) in most characteristics, but the lip pale green at the base and mid-lobe (vs. lip entirely green), fragrance reminiscent of cinnamon (vs. fragrance strong of roses), and the lip in general form similar , however in natural position the lateral lobes are twice strongly revolute, the apex appearing narrow, and the base is first involute to be able to embrace the column, and then strongly revolute giving the column the appearance of being very thick towards the apex (vs. the overall shape of the spread lip very similar, with the apical half similarly strongly revolute, but more spreading in natural position, and the basal part of the lobes only involute and embracing the column without thickening it), and the calli are arched outwards 90° (vs. calli only slightly arched).

Description: —Epiphytic to terrestrial, sympodial, caespitose, sub-erect herb to 340 cm tall. Roots 5–6 mm in diameter, basal dense, fleshy, white. Stems 340 × 1.6–1.8 cm, cane-like, simple, covered by tubular sheaths, striated, green turning red-brown when old and loosing leaves. Leaves numerous, distributed throughout stems, distichous, spreading, coriaceous; sheaths to 6.5 × 1.6–1.8 cm, tubular, striated, green, with a narrow slit opposite leaf; blade 18.0–25.0 × 5.0 cm, lanceolate, obtuse, medium green, underside lighter green, margin entire, spreading. Spathes up to 4, 10.0–14.0 × 2.0–4.0 cm, covering peduncle of inflorescence, lanceolate, conduplicate, acute, imbricating, margins entire, dry and brown when in flower. Inflorescence ca. 50 cm long, apical, paniculate, arching-nutant, flowering only once; peduncle 14.0 × 1.4 cm, terete, thick, mostly covered by sheaths, deep green; inflorescence formed by a long mid-raceme 36 cm long, and 2–3 shorter basal racemes 15.0–23.0 cm long, densely flowered, each subtended by a large bract, 9.0–15.0 cm long, similar to spathes, dark brown when flowers open and persistent until fruits open. Floral bract 3 mm long, very small, triangular, embracing. Flowers ca. 200, simultaneous, ca. 120 on mid-raceme, progressively fewer on branches, resupinate, sepals and petals green ventrally, green-brown to purple dorsally, apex of column, calli and mid-lobe of lip white to pale green, anther cream colored; fragrance reminiscent to cinnamon during daytime, stronger at night. Ovary 37.0 × 3.0 mm, terete, slightly thicker in apical half without forming any vesicle, green to red-brown. Sepals 18.0–19.0 × 9.0 mm, elliptic, acute, fleshy, thick, partly spreading, slightly arched inwards along apical half, margins entire, spreading. Petals 15.0–16.0 × 3.3 mm, partly spreading and strongly arched inwards, narrowly oblanceolate, acute, margins entire, spreading. Lip 14.0 × 18.5 mm, fused to column, deeply 3- lobed, hexagonal in outline when spread out, apex with deep, wide sinuses in natural position; lateral lobes strongly revolute, apical half of lip in natural position 12.5 × 10.0 mm, apex 3-lobed and otherwise complicated and thick; bicallose, calli strongly curved 90° outward; lateral lobes very large, 8.0 × 12.4 mm, obliquely trapezoid, apical corner acute, posterior edge square with corners broadly rounded, it is mostly free and strongly revolute with only a small part of inner margin (an arch 3 mm long, marked with an arrow in LCDP) joined to base of lip, most of lateral lobes is retrorse, distal margin of apical portion is strongly revolute and clearly visible in wide apical sinuses, apical portion appears to be straight in natural position; posterior section of lateral lobes is folded up at a 90° angle forming a in long line from posterior lateral lobe corner running lateral to the calli, free portion is then strongly revolute forming a canal which embraces column making the column appear very wide at apex; mid-lobe triangular, fleshy, slightly reflexed at apex, apex narrowly rounded, with a mid-rib running down to about middle of mid-lobe. Column 15 mm long, straight, apex obliquely truncate, with lateral wings widely rounded. Clinandrium-hood short, margin entire. Rostellum apical, slit; viscarium semi-liquid. Lateral lobes of stigma small. Cuniculus short, barely penetrating ovary, smooth, narrow. Anther 2.0 × 1.5 mm, reniform, 4-celled. Pollinia 4, obovoid, laterally compressed. Capsule not seen.

Distribution and ecology:— Presently known from two collections both from northern Peru, Cajamarca, to the northeast of the city of Chota, some 20 km apart; epiphytic and terrestrial at 2976–3050 m elevation. Flowering in January–February.

Etymology: —From the Latin retro, backwards, and lobatus, lobed, in reference to the lateral lobes of the lip which are for the most part oriented backwards, only joined to the base of the lip for a small section. In addition, they are heavily revolute and must be boiled to be able to extend them flat to see the real shape.

Conservation status:— DD. Data deficient. Known presently from two collections from northern Peru, separated by some 20 km.

Other records: — PERU: Cajamarca: Prov. Hualgayoc: Distr. Chugur : Perlamayo Capilla , 3049 m, received 9 June 2020, Dávila s.n. Digital images, AMO !

Taxonomic Discussion:— Epidendrum retrolobatum belongs to the Ferreyrae Group, proposed here, which is characterized by the sympodial, caespitose habit, the tall cane-like stems with numerous leaves, the nutant inflorescence racemose or an open panicle with few branches, the 1–2 large spathes at the base of the inflorescence, the 3-lobed lip, and medium sized flowers. The new species is recognized by the tall stems, the prominent, conduplicate spathes with similar, though somewhat smaller bracts subtending the branches of the inflorescence; the calli are arched outwards 90°, the lip when extended is hexagonal, with the apex 3-lobed and wide sinuses separating the triangular mid-lobe from the apex of the lateral lobes; however in natural position the lateral lobes are strongly revolute, the apex appearing narrow, and the lateral lobes base is first folded to be involute to be able to embrace the column and then apically strongly revolute, giving the column the appearance of being very thick towards the apex. Epiendrum ferreyrae Hágsater & Ric. Fernández is easily confused as the overall shape of the spread lip is very similar, with the apical half similarly strongly revolute, but the lip is more spreading in natural position, the basal part of the lobes are only involute and embracing the column without making it appear thickened, the calli are only slightly arched outwards. There is a difference on the shape of the lateral lobes of the type illustrated in the original description of E. ferreyrae where the lateral lobes are dolabriform, the margin forming a half circle, and the plate of a recent collection of José Edquén 829 ( Hágsater & Edquén 2023: t. 1978), where the lateral lobes are more quadrate, with right-angle corners.

Figures

FIGURE 1. Distribution map of new species of Epidendrum. Prepared by James Chamaya.

FIGURE 3. Lankester Composite Dissection Plate (LCDP) of Epidendrum retrolobatum Hágsater, Chamaya, J.Duarte & Iberico. A. Plant habit. B. Inflorescence. C. Flower, lateral view. D. Dissected perianth. E. Lip in natural position. F. Lateral lobe of lip spread. G. Ovary and column lateral view. H. Ovary and longitudinal section of column. I. Anther cap (top view and underside) and pollinarium. Prepared by Anaís Cisneros from the images by J. A. Chamaya taken from the specimen that served as the holotype.