Sarcoglyphis hiepii Aver., V.C.Nguyen & Vuong, 2022

Averyanov, Leonid V., Thai, Tran Huy, Nguyen, Van Canh, Truong, Ba Vuong, Maisak, Tatiana V., Doan, Nga Thi & Nguyen, Khang Sinh, 2022, New orchids in the flora of Vietnam (Orchidaceae, Aeridinae), Phytotaxa 572 (1), pp. 43-60 : 54-57

Sarcoglyphis hiepii Aver., V.C.Nguyen & Vuong , sp. nov.

( Figs. 7 , 8 )

Type: — VIETNAM. S Vietnam, Kon Tum Province, wild collected plant collected by Pham Dinh Hiep in Kon Tum Province, Ngoc Linh Mountains and cultivated by Nguyen Van Canh in his private garden in Buon Ma Thuot Town , herbarium and photos were prepared on 22 July 2021 by Nguyen Van Canh, s.n. (holotype LE01169270 https:// en.herbariumle.ru/?t=occ&id=141198, analytical photos and drawings made from specimen used for preparation of the type specimen – LE01122919 https://en.herbariumle.ru/?t=occ&id=101231, LE01123478 https://en.herbariumle. ru/?t=occ&id=140135) .

Paratype: — VIETNAM. N Vietnam, Son La Province, wild collected plant obtained from plant marked in Son La Province, Pha Din Pass by Nguyen Van Canh in 2018 and cultivated by Nguyen Van Canh in his private garden in Buon Ma Thuot Town , herbarium and photographs were prepared on 23 July 2020 by Truong Ba Vuong and Nguyen Van Canh, BV 750 (voucher herbarium specimen VNM 00069961 , analytical photos LE01087221 https://en.herbariumle. ru/?t=occ&id=18803) .

Etymology: —Species name honors its discoverer and orchid enthusiast, Mr. Pham Dinh Hiep.

Description:—Herb perennial monopodial epiphytic. Stem simple or basally few branching, semi-woody, erect, (6)7–11(12) cm long, covered throughout by finely verruculose leaf sheaths, in apical half with (7)8–10(12) leaves, in basal leafless part with few thick wiry flexuose white roots; internodes (5)6–11(12) mm long. Leaves subdistichous, sessile, dorsiventral, strongly conduplicate, rigid and somewhat succulent and finely verruculose, slightly arching, narrowly elliptic, (4.5)5–9(10) cm long, (0.5)0.6–1.2(1.4) cm wide, suddenly narrowing in apical part, unequally shortly bilobed at apex, with small mucro between lobes, with distinct articulation at the base. Inflorescence 1–3(5), lateral axillary raceme, (2.5)3–7(9) cm long, scape and rachis green; scape (0.8)1–4(5) cm long, erect or oblique, with 2–3 distant ovate sterile bracts 2–2.4 mm long and wide; rachis (1)1.5–4(5) cm long, more or less straight or slightly zig-zag, with (2)3–7(8) spirally arranged, lax flowers. Floral bracts dirty brownish, minute, triangular, acute, 0.8–1.2 mm long, 0.6–0.9 mm wide. Pedicel and ovary terete, longitudinally slightly grooved, (8)9–12(13) mm long, (0.9)1–1.1(1.2) mm in diameter, light green, with sparse brownish scurfy hairs. Flowers widely opening, (8)9–11(12) mm across; sepals and petals somewhat fleshy, glabrous (or sepals outside with few brownish scurfy hairs near the base), spreading, pale yellowish; lip including spur white with light purple tint and yellow side-lobes; column white; anther cap light yellowish with brown purple median longitudinal stripe. Sepals narrowly ovate, concave, blunt to obtuse, (4.5)5–6(6.5) mm long, (2.2)2.5–3(3.2) mm wide; median sepal distinctly cucullate; lateral sepals somewhat oblique. Petals narrowly lanceolate, obtuse to acute, (4.2)4.5–5(5.5) mm long, (0.6)0.7–0.8(0.9) mm wide. Lip spurred, (6)6.5–7.5(8) mm long (from spur apex to the apex of epichile), 3-lobed; side-lobes fleshy, rectangular, truncate, erect, (1)1.1(1.2) mm long, (0.7)0.8(0.9) mm tall, distal corner hook-like incurved; median lobe fleshy, obscurely 3-lobulate, (2.2)2.5–3.5(3.8) mm long and wide, entire of finely erose along the margin; lateral lobules half-round, medial twice larger than side-lobules; spur conoid, at an acute angle to the ovary, (1.8)2–2.2(2.5) mm long, (1)1.2–1.8(2) mm in diameter at base, round or obscurely truncate at apex. Spur back-wall inside with large glabrous or finely papillose callus, at front rectangular, (0.5) 0.6–0.7 mm wide, (1.1)1.2–1.3(1.4) mm long, with longitudinal groove, from sideview half-circular, 0.6–0.7 mm tall. Spur front-wall inside with two roundish lateral, glabrous or finely papillose calli placed at spur entrance, between which is placed median keel coming from the base of medial lobe to the spur and forming incomplete septum. Column half-cylindric, (3.2)3.4–3.8(4) mm tall, (1.4)1.5–1.6(1.7) mm wide, near apex at front with prominent beak-like rostellum (0.9)1–1.1(1.2) mm long; stigma at front of column, in form of large ovate concave hollow. Anther cap helmet shaped, about 0.9 mm tall, (1)1.1–1.2(1.3) mm long and wide, with large, concave, triangular beak, 1.3–1.5 mm long. Pollinia 4, bright yellow, globular, in 2 pairs. Stipe (tegula) scarious, filiform, (1.4)1.5(1.6) mm long, suddenly widening in proximal part, distally with very small roundish viscidium, about 0.2 mm in diameter. Fruits not seen.

Ecology and phenology:—Epiphyte. Primary evergreen broad-leaved forests on silicate parental rocks at elevation 1000–2000 m a.s.l. Flowers in July–August.

Distribution:— VIETNAM. Provinces: Son La (Pha Din Pass area), Dien Bien, and Kon Tum (Ngoc Linh Mountains).

Conservation status:—The species is known presently only from two locations on the border of Dien Bien and Son La provinces and in the center of Kon Tum Province. These locations placed on northern and southern Vietnam are distant from each other on about 850 km. Hence, formally its EOO may be at least 850 km 2. Nevertheless, according to available data its AOO is may be less than 10 km 2. Known populations are severely fragmented, include very few mature individuals and decline due to deforestation and habitat destruction. Due to these conditions the conservation species status may be estimated as Critically Endangered –CR (B2a,b(i-v); C1a(i,ii), C2a(i,ii); D).

Notes:—New species morphologically is most close to known from N Thailand and Yunnan, S. yunnanensis Z.H.Tsi ( Tsi 1984: 476) and described from northern Vietnam sympatric species, S. brevilabia Averyanov (2012: 133) . However, it differs well from these species in plant habit and floral morphology. Their morphological features are summarized on the Table.

Figures

FIGURE 7. Sarcoglyphis hiepii Aver., V.C.Nguyen & Vuong, sp. nov. A. Flattened flowering plant. B. Portion of inflorescence. C. Leaves, adaxial and abaxial side. D. Leaf apex, adaxial and abaxial side. E. Flower, frontal view. F. Flattened sepals and petals. G. Pedicel, ovary, column, and lip, side view. H. Lip, view from above. I. Lip, view from below. J. Lip, side view. K. Lip. Sagittal section. L. Column with operculum. M. Column with operculum and pollinarium removed. N. Column, half side view. O. Anther cap, view from above and from below. P. Pollinarium, view from different sides.All photos by Truong Ba Vuong made from specimen BV 750, photo correction and design by L. Averyanov and T. Maisak.

FIGURE 8. Sarcoglyphis hiepii Aver., V.C.Nguyen & Vuong, sp. nov. A. Flowering plant. B. Inflorescence. C. Intact flower, half-side view. D. Intact flower, frontal view. E. Ovary, column, and lip, side view. F. Ovary, column, and lip, sagittal section. G. Column and lip, frontal view. H. Lip, view from above. I. Epichile and spur, apex and spur back-wall removed. J. Column, back-wall of spur, front-wall of the spur removed. K. Anther cap, view from above, view from below, and side view. L. Pollinarium, frontal view and view from behind. All drawings by L. Averyanov and T. Maisak from specimen Truong Ba Vuong BV 750.