Begonia dimorpha S.Julia

국표에 없다.

• Sandakania 20: 59. (2015) 

• This name is reported by Begoniaceae as an accepted name in the genus Begonia (family Begoniaceae).

  The record derives from IPNI (data supplied on 2024-11-15) which reports it as an accepted name (record ten:padme.rbge.org.uk:brcwfo-0001330380 )

Diagnostic Description

It is similar to Begonia malachosticta Sands (1990: 64) in being a cane-like begonia with large, pendent, spotted leaves and female flowers located in the lower leaf axils with the male inflorescences terminal. However, B. dimorpha is different in having white or pink spots in the young leaves, disappearing in the adult leaves that are plain green and the flowers are not produced on the main stem but on horizontal lateral branches.

NOTES. A striking species when young because of its bright white or pink spotted leaves. Unfortunately, this variegation is lost in mature plants, or it would be an attractive ornamental plant.

Notes. In Kalimantan this species is only recorded from limestone, which differs from the type locality. Our collections and field observations in the Karangan area showed a range of tepal number in the male flowers (2, 3 and 4); the type has 2 tepals. There is a similarity between Begonia dimorpha and the earlier described B. tawaensis Merr. (also from the Tawau Hills) which requires further investigation.

• Provided by: [B].The Begonia TEN / Begonia Resource Centre (Royal Botanic Garden Edinburgh)

Morphology

Cane-like glabrous begonia, erect, to 117 cm tall, main stem unbranched with lateral horizontal branches towards the apex. Stems reddish, becoming brown and woody, c. 5 mm diameter, internodes 5.1–9.2 cm long, thicker at the nodes. Stipules pale green, lanceolate, 16–21 × 5–10 mm, midrib keeled outside, margin entire, apex setose, seta to 8 mm long, caducous. Leaves alternate, distant, oblique, hanging downwards; petiole reddish, terete, on main stem 4.4–6.1 cm long, on lateral branches 0.9–1.9 cm long; lamina of young plants with rows of white or pink spots between the veins and with a white or pink line around the margin; leaves of mature plants plain dark green with a red blotch at the junction of the lamina and petiole, in juvenile and mature leaves completely deep magenta or tinged magenta beneath, matt, slightly fleshy in life, ovate, asymmetric; lamina on the main stem 10.3–16.3 × 6.2–8 cm, broad side 4.1–5.1 cm wide, basal lobe rounded, 3.7–5.6 cm long, margin remotely and minutely toothed, apex attenuate, lamina of lateral branches smaller, c. 8.7 × 4.4 cm, broad side c. 2.6 cm wide, basal lobe c. 2.3 cm long; venation palmate-pinnate, with a pair of veins at the base of the midrib, 2–3 veins on either side of the midrib, branched once or twice, 4 veins in the basal lobe, slightly impressed above, beneath paler and slightly prominent. Inflorescences protogynous; female flowers axillary, 1–3, each single from lower leaf axils; male inflorescences terminal, cymose, few-flowered, c. 3.8 cm long, peduncle thin, c. 3.4 cm long, pale green or magenta. Bracts pale green, narrowly lanceolate, c. 11 × 4 mm, margin entire, apex setose, seta c. 0.3 cm long, persistent. Bracteoles minute. Male flower (bud) cherry red or white outside, pedicel cherry red or white, c. 4 mm long; tepals 2, oval, c. 4 × 4 mm, margin entire, apex broadly acute; stamens 56–60, cluster subglobose, sessile; filaments pale yellow, 0.7–1 mm long; anthers pale yellow, obovate or oblong, 0.5– 0.6 × c. 0.3 mm, apex emarginate. Female flower: pedicel c. 4 mm long, pale green; ovary green tinged pink, c. 3 × 2.5 cm, wings 3, subequal, locules 3, placentas bilamellate with many ovules on both surfaces; tepals 5, all white, elliptic, 4 larger c. 11 × 7 mm, the fifth narrower c. 11 × 5 mm, margin entire, apex broadly acute; styles 3, brownish yellow, c. 3.5 mm long, divided to base; stigma white, papillose forming a continuous twisted band. Capsules broadly triangular in outline, 1.7–3.0 × 1.9–2.9 cm, wings subequal, narrowed proximally, truncate distally, tip acute, 0.8–1.0 cm wide, thinly fibrous, dehiscing between locules and wings, dangling on fine thread-like pedicel, 2.1–3.3 cm long.

• Provided by: [B].The Begonia TEN / Begonia Resource Centre (Royal Botanic Garden Edinburgh)

Habitat

Occasional in alluvial forest, but only found fertile on very steep, lightly shaded slopes at 310 m elevation.

• Provided by: [B].The Begonia TEN / Begonia Resource Centre (Royal Botanic Garden Edinburgh)

Distribution

Danum Valley in Sabah on alluvial soils and around Karangan in East Kalimantan on limestone karst.

Borneo. Endemic to Sabah (Danum Valley Conservation Area, Lahad Datu).

• Provided by: [B].The Begonia TEN / Begonia Resource Centre (Royal Botanic Garden Edinburgh)

Begonia dimorpha S.Julia (worldfloraonline.org)

 

https://youtu.be/RruEuCtC05g?t=2436