Begonia yiii Kiew & S.Julia, 2013

Sang, Julia, Kiew, Ruth & Yiing, Ling Chea, 2018, The Begonia flora of Gunung Mulu and Gunung Buda National Parks, Sarawak, Borneo, including five new species, Phytotaxa 381 (1), pp. 58-79 : 77-78

20. Begonia yiii Kiew & S.Julia ( Figure 11 )

Phytotaxa 99(1) (2013) 28. Type: — MALAYSIA. Borneo. Sarawak. Marudi District: Gunung Mulu NP, Hidden Valley, 21 March 1990, Yii & Talib S 58706 (holotype SAR!).

Erect begonia to 40 cm tall, flowering when 20 cm tall. Stem ca. 7 mm thick, indumentum of dark brown appressed hairs (also on petiole); internodes 3–3.5 cm long. Stipule pale green or greenish red, lanceolate, keeled, 13–17 × 9–10 mm, margin serrate, apex setose, seta 1.5 mm long, persistent. Leaves alternate, held slightly vertical. Lower petioles ca. 3.5 cm long, upper petioles 1.5–2 cm long, stout, grooved above. Lamina thickly succulent, glossy, broadly obovoid, 6–11 × 4.3–6.5 cm, base rounded, slightly unequal, margin with distant, minute teeth pronounced towards the apex, apex acute, green above and paler below or bronzy green above, sometimes with silvery spots and deep magenta below, glabrous above, sparsely hairy on veins below; venation pinnate, 1 pair at the base, midrib bifurcating at the base and branching towards the apex, 2–3 veins on either side of midrib, veins greenish or reddish and impressed above, magenta and prominent below. Inflorescence protogynous, in upper leaf axils, racemose, 8–16.6 cm long, peduncle 2.5–4.5 cm long. Lower bracts subtending branches, 2–3.5 cm long, pale green, broadly ovate, basal bracts 13–15 × 8– 9 mm, keeled, margin slightly ciliate, persistent; upper bracts ca. 7 × 16 mm, pale green, reddish, persistent; bracteoles ca. 11 × 12 mm, white tinged pink, broadly lanceolate, folded in half, margin sparsely ciliate, persistent. Male flower: pedicel pinkish, 8–10 mm long, sparsely pubescent; tepals 4, white or pinkish, margin entire, apex rounded, glabrous, outer 2 tepals elliptic or rounded, 11–12 × 7–11 mm; inner 2 tepals lanceolate, 6–8 × 2.5 mm; stamens yellow, 48–50, cluster globose; filaments pale yellow, 0.6–1 mm long; anther yellow, obovate 0.4–0.5 × 0.2 mm. Female flower: pedicel ca. 4 mm long, whitish, sparsely pubescent; tepals 5, white or pinkish, margin entire, glabrous, outer 4 tepals oval, ca. 7 × 5 mm, apex rounded; inner tepal ca. 5 × 3 mm, apex acute, ovary ca. 10 × 16 mm, wings 3, unequal, ca. 4 mm wide, locules 3, placentas 2 per locule; style pale yellow, 2–2.5 mm long, stigma anchor-shaped. Capsule on a thread-like branch, 3 capsules per infructescence, capsule 7–9 × 14–15 mm, wings unequal, smaller wing 4–5 mm wide, larger wing 6–8 mm wide; pendent on a pedicel ca. 2.5 mm long.

Distribution: — MALAYSIA. Borneo. Sarawak. Endemic in Gunung Mulu NP.

Habitat: —More common in lower montane forest on Gunung Mulu at 1180–3000 m elevation and in forest on shale at 300–850 m elevation but also in limestone forest and sometimes growing in creeks, at 200–900 m elevation.

Additional specimens examined: — MALAYSIA. Borneo. Sarawak. Marudi District: Gunung Mulu NP – Opposite Long Bala, Yii & Talib S 58811 (SAR); unspecified locality, Lai & Jugah S 44160 (SAR), Martin S 38153 (SAR), Martin S 38188 (SAR), Martin S 37057 (SAR); Camp 3, Gunung Mulu, Yii & Talib S 58224 (SAR), Yii & Talib S 58203 (SAR), Chai S 36457 (SAR), Burtt & Woods B 2120 (SAR), Burtt & Woods B 2086 (SAR); Path from Melinau Paku, Anderson S 4519 (SAR), Anderson S 4518 (SAR); Path from sub-camp 2 to sub-camp 3, Lewis 301 (SAR); path from sub-camp 1 to sub-camp 2, Lewis 278 (SAR), Julia et al. SFC 6673 (SAR), Lewis 279 (SAR); sub-camp 2, Lewis 294 (SAR); ridge above Melinau Gorge, Kiew RM 450 (KEP).

Notes: —This expanded description is based on living material that became available during the recent survey. Julia et. al (2013) noted that B. yiii belonged in an unplaced section; however, as more fertile materials has become available and the number of placentas can be ascertained, it is obvious that this species belongs to Section Petermannia .

Figures

FIGURE 11. Begonia yiii Kiew & S.Julia. A & B. Habit showing individual with plain green leaves; C. Habit showing individual with spotted leaves; D. Stipule; E. Inflorescence showing bracts and bracteoles; F. Male flowers; G & H. Female flowers; I. Transverse section of female flower.All photos from SFC 6673 by S. Julia.