Begonia montaniformis
Begonia montaniformis
| Species | montaniformis |
|---|---|
| Region | Thanh Hoa Province, Northern Vietnam |
| Country | |
| Year Described | N/A |
| Plant Type | Rhizomatous |
| Section | |
| Chr 2n | 30, 31, 32, 33 |
Species Information
Description
- **Growth Habit:** Herbaceous, monoecious, perennial, and rhizomatous. - **Rhizome:** Stout, creeping, up to 30 cm long, 1-2.3 cm thick, with internodes 0.5-1.7 cm long, villous near the petiole insertion. - **Stipules:** Pale green to pinkish, ovate-triangular, 0.7-1.4 cm long, 0.6-1.3 cm wide, strongly keeled, abaxially hairy along midrib, margin velutinous, apex aristate with an arista of about 0.2 cm. - **Petiole:** Red to greenish-purple, terete, 7-20 cm long, 0.4-0.7 cm thick, densely white villous. - **Leaves:** Alternate, blade asymmetric, ovate to widely ovate, 11.5-19 cm long, 8-13.5 cm wide, with a broad side measuring 6-8 cm wide. The apex is acuminate to acute, and the base is strongly oblique-cordate. The margin is repand to shallowly denticulate and ciliate. The leaves are thickly chartaceous to succulent. Adaxially, they are blackish-malachite green, purplish-olive, or dark bluish-brown, with a silvery green zone along primary and secondary veins. The leaf surface is bullate, with conical bullae measuring 0.4-0.8 (-1) cm high and 0.5-0.8 cm across, tipped by 2-4 (-6) peak-like hispidulous protrusions. Abaxially, the leaves are pale green, reddish on the hollow bullate region, and densely brownish-white tomentose on veins. Venation is palmate with 7-9 primary veins, a distinct midrib, 2-4 secondary veins on each side, and tertiary veins that are percurrent or reticulate, sometimes spiderweb-like near petiole attachment, with minor veins reticulate. - **Inflorescences:** Axillary, arising directly from the rhizome, with dichasial cymes branching 3-8 times. Peduncles are 11-28 cm long, tomentose to subglabrous. Bracts and bracteoles are caducous, yellowish-green to reddish, with ovate bracts (about 1 cm long, 0.5 cm wide) and boat-shaped bracteoles. - **Staminate Flower:** Pedicel 1.1-2 cm long. Tepals number 4, with outer 2 broadly ovate to obovate-orbicular (7-12 mm long, 6-10 mm wide) and inner 2 greenish, elliptic (6-8 mm long, 3-5 mm wide). Androecium is sub-actinomorphic, spherical, about 5 mm across, with 55-90 stamens. Filaments are fused at the base into a column, and anthers are yellow, slightly compressed, obovate, and about 1 mm long. - **Pistillate Flower:** Pedicel 1.4-2 cm long. Tepals number 3, with outer 2 suborbicular or broadly ovate, abaxially reddish-green and adaxially yellowish-greenish (8-12 mm long, 9-13 mm wide), and inner 1 yellowish-greenish, elliptic (5-8 mm long, 2.5-4.5 mm wide). The ovary is reddish-green, trigonous-ellipsoid (5-9 mm long, about 3 mm thick excluding wings), sparsely sessile-glandular, and 3-winged. The wings are unequal, reddish-green, with lateral wings measuring 2-3 mm wide and an abaxial wing crescent-shaped (3-8 mm wide). Styles number 3, fused at the base, and are yellow or greenish, about 4 mm long, with a spirally twisted stigma. - **Capsule:** Trigonous-ellipsoid, 7-11 mm long, about 3-4 mm thick (wings excluded), greenish or reddish when fresh. The wings are unequal, with lateral wings measuring 2-4 mm wide and an abaxial wing crescent-shaped (4-9 mm wide).
Distribution and Ecology
Lithophytic herb on shady cliff. Endemic to Ba Thuoc District, Thanh Hoa Province, Northern Vietnam. Known only from the type locality. It grows in primary evergreen seasonal broad-leaved closed lowland forest on crystalline marble-like highly eroded limestone, very steep rocky slopes, and cliffs at elevations of 450-600 m.
Etymology
The specific epithet refers to the leaf surface with dense conic bullae, reminiscent of the peak clusters in Sino-Vietnamese limestone karst landforms.
Notes
Begonia montaniformis shares some similarities with B. ferox and B. nahangensis but can be distinguished by several features, including stipule margin, vein color, bullae characteristics, and flower color. A detailed comparison of the new species with B. ferox and B. nahangensis is provided in Table 5.
References
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Photos
