Begonia karangputihensis Girm., 2015

Hughes, Mark, Girmansyah, Deden & Ardi, Wisnu Handoyo, 2015, Further discoveries in the ever-expanding genus Begonia (Begoniaceae): fifteen new species from Sumatra, European Journal of Taxonomy 167, pp. 1-40 : 17-19

Begonia karangputihensis Girm. sp. nov. § Reichenheimia

urn:lsid:ipni.org:names:77151643-1

Figs 2 , 8

Diagnosis

Begonia karangputihensis differs from the peltate B. goegoensis which is also native to West Sumatra in being a smaller plant, with smaller (up to 7 cm wide, not c. 9–15 cm wide), less rugose leaves, terete petioles (not triangular) and flowers with flat membranous tepals (not cup-shaped and fleshy).

Etymology

The epithet is derived from Bukit Karang Putih, an area of limestone within Lubuk Kilangan district, West Sumatra, near the Semen Padang mine. In English the name of the area means “white coral hill”.

Type

SUMATRA: West Sumatra, Bukit Karang Putih, near Padang, 364 m, 17 Jun. 2011, Puglisi, Hughes, Girmansyah & Roki CP 53 (holo-: BO; iso-: E).

Additional material

SUMATRA: West Sumatra, Bukit Karang Putih, 16 Feb. 1981, Hotta et al. 345 ( ANDA ); ibid., 28 Mar. 1989, Masniati 01 ( ANDA ); ibid., 17 Jul. 2011, Puglisi et al. CP 57 ( BO, E).

Description

Erect lithophytic acaulescent herb, 15–20 cm tall, often found in shallow caves; stem rhizomatous, internodes 0.5–1 cm long. Stipules persistent, glabrous, 10 mm long, broadly triangular, keeled only towards the apex, apex acute. Leaves: petiole 8–15 cm long, terete, glabrous; lamina basifixed on juvenile plants and peltate on mature individuals, basifixed leaves with base cordate, lobes not overlapping, peltate leaves ovate, subsymmetric to symmetric, 8.5–11 × 5–7 cm, upper surface light green, flushed reddish in centre on mature plants, glabrous on both sides, venation palmate-pinnate with 7(–8) main veins; margin sub entire to shallowly dentate, with cartilaginous recurved teeth at the end of the veins, apex acute to shortly acuminate. Inflorescences axillary, total length 15–20 cm, cymose, branching 2–5 times, with 10–20 flowers, bisexual, protandrous; primary peduncle 12.5–17 cm long; bracts caducous, basal pair sub-orbicular, 5 × 4 mm, subsequent pairs obovate, c. 3 mm long, margin entire. Male flowers: pedicel 10–18 mm long, glabrous; tepals 4; outer tepals 2, sub orbicular, membranous, 9 × 9 mm, white blushing pink at the base adaxially, glabrous, inner tepals elliptic, 7 × 3 mm, white; androecium yellow, globose, on a 0.5 mm long column; stamens 70–80; filaments unequal, basal ones shortest, 0.25–0.75 mm long; anthers 0.6 mm long, oblong-obtriangular, dehiscing through slits the whole length of the anther, slits positioned laterally. Female flowers: pedicel 10–15 mm long, glabrous; ovary green, glabrous, 10 × 10 mm including the wings; capsule ellipsoid, 8 × 4 mm, ellipsoid, 3-locular, placentae entire; wings 3, subequal, 10 × 2 mm, rounded, 2 slightly smaller ones rounded at the base, the other retuse; tepals 3–4, outer tepals 2, 8 × 8 mm, suborbicular, white, inner tepals 1–2, elliptic, 7 × 3 mm, white; stigmas 3, deep yellow, forked once and once spirally twisted, semi-persistent. Fruit recurved on a stiff 10–20 mm long pedicel, the two smaller wings held horizontally forming a splash cup; total size 6–9 × 9–14 mm, wings 2–4 mm wide; apex obtuse.

Distribution and habitat

Endemic to the Bukit Karang Putih limestone near Padang in West Sumatra ( Fig. 2 ), where it grows on cliffs and in shallow caves.

Conservation status

We assess B. karangputihensis to be Vulnerable under criteria VUD2 ( IUCN 2012), as the type locality is only 1 kilometre away from an industrial limestone mine and just outside the edge of Kerinci Seblat National Park.

Figures

Fig. 2. Map of Sumatra showing the full known species distributions based on collection localities. Each point may represent more than one collection.

Fig. 8. Begonia karangputihensis Girm. sp. nov. A. Habit. B. Male flower. C. Plant with young leaves showing transition from basifixed to peltate. D. Mature fruit on a recurved pedicel. E. Ovary. F. Female flower.A,C, D taken at the type locality of Bukit Karang Putih; the floral insets B, E, F were photographed from plants in cultivation at the Royal Botanic Garden Edinburgh, accession 20111545. Scale bars on insets: B, D–F = 1 cm; C = 10 cm.