Begonia sirindhorniana
Species Information[edit]
Classification and Distribution[edit]
Begonia sirindhorniana is a species of Begonia endemic to South-Western Thailand, specifically in the Suan Phueng District of Ratchaburi Province. It is known from a single location along the Thailand-Myanmar border.
Habitat[edit]
This species is found in hill evergreen forests at an altitude of approximately 1,050 meters.
Characteristics[edit]
Begonia sirindhorniana is a small, monoecious caulescent herb, typically reaching a height of 5–10 cm. Its stem is tuberous, with an ovoid to subglobose shape and fibrous roots. The aerial stem is erect or ascending, fleshy, and may or may not branch. The stem is densely covered in white velvety hairs. The leaves are generally 2–5 per plant, with petioles ranging from 1.5 to 6 cm in length. The leaf blades are membranaceous, ovate to ovate-lanceolate in shape, and measure 2–6 by 1.2–4 cm. The base of the leaf blade is cordate, either symmetric or subsymmetric, while the apex is acute to acuminate. Leaf margins are irregularly dentate. The venation is palmate with 7–9 veins, which are prominent on the lower leaf surface.
Flower Details[edit]
The inflorescences of Begonia sirindhorniana are monochasial cymes, axillary, and bisexual. Staminate flowers are basal, while pistillate flowers are distal, and the species exhibits protandry. Staminate flowers have 4 tepals, with pale pink coloration. The outer 2 tepals are orbicular to ovate-orbicular, measuring 5.5–1.2 by 4.5–9 mm. The inner 2 tepals are linear-oblong, measuring 3–6 by 0.8–2 mm. Stamens are actinomorphic, and there are 18–25 of them. The filaments are fused at the base, and anthers are obovoid, dehiscing by apical pore-like slits near the tip.
Pistillate flowers have 2–3 tepals with pale pink coloration. The outer 2 tepals are orbicular, measuring 3–5 by 3.5–4.5 mm, while the inner 2 tepals are oblong, measuring 0.8–1.5 by 0.6–0.8 mm. The styles are 3 in number, fused at the base, with crescent-shaped stigmas. The ovary is inferior, with 3 subequal wings, and it is 3-locular with bilamellate placentas.
Etymology[edit]
The epithet "sirindhorniana" is given in honor of Her Royal Highness Princess Maha Chakri Sirindhorn for her dedication to science and encouragement of conservation in Thailand.
Comparison to Similar Species[edit]
Begonia sirindhorniana shares some morphological similarities with Begonia lushaiensis C.E.C. Fisch. However, it differs in being a smaller plant (5–10 cm tall vs. 10–30 cm tall in B. lushaiensis), with most leaves arising from the tuber (vs. most leaves on an erect stem), lanceolate bracts (vs. sub-orbicular), ovate leaves (vs. lanceolate), a monochasial cyme inflorescence (vs. racemose-cymose), and having 2–3 tepals in pistillate flowers (vs. 4–5 tepals).
References[edit]
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External Links[edit]
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