Distichochlamys-a new genus from Vietnam

1. Distichochlamys citrea M.F.Newman
Distribution: Viet Nam, Bach Ma Nature Reserve
Description: Small herb to 35cm, rhizome c.5cm below ground level. Leafy shoots close together producing a dense clump, (l-)2(-3)-leaved, with basal sheaths to 10 x 2.5cm which dry to a papery texture by anthesis. Plane of distichy of leaves parallel to rhizome. Leaf to 42cm long; petiole to 20cm, stiff, deeply channelled on adaxial surface, very sparsely silky hairy, shiny; ligule small, c.5mm long, drying and decaying by anthesis; leaf blade 17-22 x 8.3-10.7cm, broadly elliptical, midrib markedly eccentric, base cuneate or rounded, equal or not, apex shortly acute, glabrous above, slightly shiny, sparsely silky hairy below, especially on the midrib, glossy. Inflorescences terminal.

Distichochlamys citrea M.F.Newman
Distichochlamys citrea M.F.Newman
Distichochlamys citrea M.F.Newman

Distichochlamys citrea M.F.Newman; Family Zingiberaceae. Regional distribution in Cuc Phuong, Vietnam. This is the type species of this genus, green leaves and yellow flowers, with red streaks between bud.
2. Distichochlamys orlowii K.Larsen & M.F. Newman

Distribution: Vietnam, Buenloy, Ankhe District, Provice Gia Lai


Distichochlamys orlowii K.Larsen & M.F.
Distichochlamys orlowii K.Larsen & M.F.

Distichochlamys orlowii K.Larsen & M.F. Distributed in a narrow area in the village of An Khe district, Gia Lai province.
3. Distichochlamys rubrostriata W. J. Kress & Rehse
Distichochlamys rubrostriata
Distichochlamys rubrostriata
Distichochlamys rubrostriata W. J. Kress & Rehse
Distribution: Cuc Phong National Park, Ninh Binh Province, Vietnam.
Description: Small evergreen herb to 30 cm, rhizome to 15 mm diameter, white to purple internally. Leafy shoots producing a dense clump, (1)-2-(3)-leaved, with deep ma- roon, glabrous basal sheaths ca. 2.5 x 6 cm; plane of distichy parallel to rhizome. Leaves to 40 cm in length, glabrous; petiole to 14- 23 x 0.6 cm, maroon at base from distinct red pigmented cells, transitioning to green at apex, scattered with minute white spots, can- aliculate, maroon throughout groove, margin membranous; ligule small, 3-4 mm in length, bilobed, becoming papery; blade 18- 20 • 9-12 cm, broadly elliptic, midrib prominent below, base subattenuate to slightly truncate, equal or subequal, apex apiculate and often papery, adaxial surface slightly darker green than abaxial. Inflores- cence terminal on leafy shoots, erect to 5.5 cm; peduncle 4 - 6 cm, glabrous, translucent with scattered maroon pigmented cells (ap- pearing pink) at base fading to translucent green by first fertile bract; rachis inclined slightly at first fertile bract, continuing straight; inflorescence bracts 22-24 x 17- 20 mm, distichous and densely imbricate, opening only to one side of rachis, deviat- ing approximately 10-30 ~ from vertical axis, glabrous, light green with maroon pig- mented dots clustered near veins, apices acute; cincinni 7-8, containing 2-3 flowers of which 1-2 do not develop; flowers ma- ture sequentially in waves from base to apex of inflorescence; bracteoles tubular, 19-25 x 8-17 mm, membranous, glabrous and transparent with maroon veins. Flowers conspicuous; calyx tubular, 11-13 mm long, trilobed and deeply cleft to ca. 7 mm abaxially, colorless with maroon pigmented dots; corolla tube 20-30 ram, translucent yellow, glabrous, trilobed with lobes 15-17 mm, reflexed, the two lobes nearest label- lure often overlapping at anthesis; lateral staminodes 17-22 x 10 mm, obovate, spreading, glandular hairy throughout, lem- on yellow with a linear dark red mark ex- tending 1/5 to 1/fithe length of the lobe, fol- lowing main veins; labellum 16-18 x 13- 16 mm, obovate, bilobed, cleft extending 7 mm, lemon yellow with darker yellow regions extending down lobes, glandular hairy along margins and down throat, lobes abaxially flared and slightly overlapping at the tips; fertile stamen with filament 4 mm long, yellow, glabrous, anther 5 x 3 mm, thecae parallel and encircling style, fertile throughout, densely glandular hairy throughout, crest extended less than 1 mm beyond thecae; ovary trilocular, 2-3 x 2 mm, glabrous, pale green, placentation ax- ile; stigma cup-shaped, fringed with hairs; epigynous (stylodial) nectaries two, linear, 7 mm long, pale yellow. Fruits unknown.
4. Distichochlamys benenica Q.B.Nguyen & Škorničk.
Distichochlamys benenica Q.B.Nguyen & Škorničk.
Distichochlamys benenica Q.B.Nguyen & Škorničk.
Distichochlamys benenica Q.B.Nguyen & Škorničk.
Distribution: Vietnam, Thanh Hoa Province, Nhu Thanh District, Ben En National Park, altitude c. 120–150 m, mixed evergreen forest, limestone
Description: Terrestrial rhizomatous herb to 60 cm tall. Rhizome sympodially branching, c. 7–13 mm in diam., light brown externally, cream white to ochraceous internally with prominent citrol smell, sheathing bracts not seen (decaying very soon and leaving only scars on mature rhizomes), root tubers fusiform, 3–8 cm long, 7–10 mm in diam., light brown externally, cream white to ochraceous internally. Leafy shoots with a single leaf, tightly arranged forming clumps. Sheathing bracts 1–3, inner one to 6 × c. 2 cm wide, outer ones gradually smaller, papery and decaying fast by the time of flowering, glabrous. Leaf sheaths 3–5 cm, deep purple, glabrous. Ligule bilobed, c. 3 mm long, papery, glabrous, soon decaying. Petiole 8–25 cm long, canaliculate, dark red-purple, glabrous. Lamina oval to obovate, unequal, 15–28 × 10–14.5 cm, plicate, green above, lighter green with purple shading at the apex beneath, apex subacute to nearly rounded, base rounded to slightly cordate. Inflorescence to 15 cm, partly hidden in leaf sheath. Peduncle 3–6 cm, c. 4 mm in diam., glabrous, with 2–3 sterile bracts, the outer ones papery, to 6 cm long, decaying fast, the inner ones red purple, c. 3–5 cm long, glabrous, 2 cm broad, apex acuminate. Spike 6–10 cm long, consisting of 8–13 bracts. Bracts ovate with acute apex; with more or less pink-red tinge, 1.8–3.2 × 1–2.2 cm, glabrous, enclosing cincinnus of 2–3 flowers. Bracteoles 13–23 mm long, 8–20 mm in circumference, tubular in basal 2–6 mm, with one keel, translucent white with pink tinge at apex, sparsely shortly hairy. Calyx 15–19 mm long, translucent white with slight pink tinge, glabrous but sparsely hairy at apex (margins of teeth), 3 teeth, unilateral slit 8–10 mm. Floral tube 18–21 mm, pinkish at base, light yellow towards apex, glabrous externally. Dorsal corolla lobe ovate, 16–23 × 6–7 mm, semi- translucent yellow with red tinge at apex, glabrous, apex mucronate, mucro 2.5 mm, shortly hairy. Lateral corolla lobes ovate, 16–20 × 6–8 mm, semi-translucent yellow with red tinge at apex, apex slightly concave, glabrous. Labellum broadly spathulate, bilobed at apex, 21–23 mm long, 18–21 mm broad at apex, c. 5 mm broad at base, lobes more or less rounded, split c. 7–8 mm, yellow with red-orange central patch, with short glandular hair. Lateral staminodes obovate, 20–24 × 7–10 mm, yellow, covered with glandular hairs. Stamen 7 mm long, filament 2.5–3 mm long, pinkish at base, light yellow towards apex, glabrous, anther 5 mm long, anther thecae dehiscing along their entire length, connective tissue deep yellow, covered with glandular hairs, anther crest c. 1 mm long. Epigynous glands two, 4–6mm, cream white sometimes with slight pink tinge at base, ochraceous towards apex, sometimes connate. Ovary trilocular with axile placentation, 2–3 mm long, 2 mm in diam., cream white with slight pink tinge at apex, densely hairy. Style white, glabrous, stigma white, apex ciliate, quadrangular with transverse ciliate ostiole. Fruits unknown.
Habitat and phenology: This species occurs in evergreen broad-leaved mixed forest, on limestone, at elevations about 100–200 m. It flowers in March to April. 
References
Larsen, K. & Newman, M. (2001) A new species of Distichochlamys from Vietnam and some observations on generic limits in Hedychiae (Zingiberaceae). Nat. Hist. Bull. Siam Soc. 49: 77.
Newman, M.F. (1995) Distichochlamys, a new genus from Vietnam. Edinburgh J. Bot. 52(1): 65–69.
Rehse, T. & Kress, W.J. (2003) Distichochlamys rubrostriata (Zingiberaceae), a new species from Northern Vietnam. Brittonia 55(3): 205–208.

Quoc Binh Nguyen, Jana Leong-Škorničková (2012) Distichochlamys benenica (Zingiberaceae), a new species from Vietnam; Gardens’ Bulletin Singapore 64(1): 195–200.  


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