Disporum Salisb.

Sarapan, A., Chamchumroon, V., Hodkinson, T. R. & Suwanphakdee, C., 2024, Taxonomic revision of Disporum (Colchicaceae) from Thailand including four new species, Blumea 69 (2), pp. 139-160 : 140-141

Disporum Salisb.

Disporum Salisb.(1812) 331; D. Don (1825) 50,(1839) 44; Baker (1874) 588; Benth.& Hook.f. (1883) 831; Hook.f. (1894) 359;Q. Jones (1951) 5; Backer & Bakh.f. (1968) 94; Char. (1973) 88; Jessop (1979) 217; H. Hara (1988) 163; B.Nord. (1998) 184; Songyun & M.N.Tamura (2000) 154. — Type: Disporum pullum Salisb. , nom. illeg. = Uvularia chinensis Ker Gawl. (= D. cantoniense (Lour.) Merr. ).

Perennial erect herbs. Rhizomes short vertical and horizontal, creeping, densely noded with storage roots. Roots fleshy. Aerial stems erect and arching, simple or distally 2–7-branched; lower part of aerial stem rounded with adventitious roots at first and second node, the axis with two grooves, green or dark purple; the upper part rounded or rectangular, the axis with ridges, green. Cataphylls 2 – 9, sheathing lower part of stem, papery, glabrous, green or brown, venation palmately netted. Leaves simple, alternate or opposite, lamina narrow-lanceolate, elliptic or ovate, lower surface glabrous, upper surface glabrous or with peltate scales, base obtuse, margin dentate, renovate or involute, apex acuminate with mucro, papery when dried, glabrous, green, venation palmately netted; petiole absent or very short, V-shaped, heart-shaped or crescent shaped, with or without marginal ridges, green or light green, papillose on the ridges. Inflorescences axillary, leaf-opposed, umbellate, 2–11-flowered, pendulous; peduncle rectangular, papillose on the ridges, green. Flowers campanulate, tubulate or rotate; pedicel rectangular, papillose on the ridges, green. Perianth 6 tepals in 2 whorls, lanceolate, obovate, elliptic, oblong or ovate, white, pink or purplish red, base cuneate, glabrous or scabrous, margin entire or dentate, apex acute to acuminate, papery or membranous when dried, 1– 3-keeled, venation reticulate. Spurs gibbous or straight, rounded or cylindrical or funnel-shaped, glabrous or densely scabrous, apex obtuse, white, green, or dark red, 1- or 3-ridged, thick or membranous, glabrous or scabrous. Stamens 6; filament flat, narrowobclavate to oblong, white, green, pink or dark purplish red, glabrous or papillose; anthers 2-thecate, basifixed or dorsifixed, oblong, yellow or purplish red, opening extrorse with longitudinal slits. Ovaries superior, oblong, obovate or obovate to oblong, glabrous, 3-locular, 6 ovules (2 ovules/locule), placentation axi- lar; style oblong, with 3 shallow grooves, white or dark dull red, glabrous or densely papillose; stigma trifid, revolute or slightly revolute. Fruit a berry, globose or oblate, glabrous, pendulous, blue to black. Seeds 1–5, subglobose or triangular, brown or light brown, surface rough when dried.

Anatomical characters

STEM. Cuticle echinate. Epidermal cells rounded or rectangular. Ground tissue consisting of parenchyma and sclerenchyma; forming a ring. Vascular system closed-collateral; lower part rounded to sub-rectangular; parenchyma accumulating tannin.

PETIOLE. Cuticle echinate. Epidermal cells rounded or rectangular; papillae present or absent. Ground tissue comprising parenchyma and collenchyma; some species accumulate tannin in ground tissue . Vascular system closed-collateral with sclerenchyma surrounding the bundles; vascular bundles 8–19, round or elliptic.

LEAVES. Leaf in surface view: epidermal cells with sinuous anticlinal walls; adaxially peltate scales present or absent; abaxially glabrous, stomata anomocytic (hypostomatic). Leaf in transverse view: dorsiventral. Epidermis with 2 zones, costal and intercostal with smooth or echinate cuticle. Palisade: 1 or 2 layers, cells rectangular. Spongy mesophyll sparse, cells irregularly shaped. Midrib: vascular system U-shaped to V-shaped. Margin: involute or revolute. Upper epidermal cells with smooth or echinate cuticle. Lower epidermal cells with echinate cuticle.

Pollen morphology

Monad, asymmetrical or bilateral in equatorial view, spheroidal, sub-spheroidal or prolate; equatorial axis 27 ± 0.60–44 ± 0.72 µm long; polar axis 25 ± 0.73–40 ± 0.53 µm long; 2 –3-porate or monosulcate; exine thickness 1–3 ± 0.71 µm; rugulate with granulate surface, or rugulate with perforate ornamentation.