Begonia kudoensis 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 : 23-25

Begonia kudoensis Girm. sp. nov. § Reichenheimia

urn:lsid:ipni.org:names:77151646-1

Figs 4 , 11

Diagnosis

Closest to B. halabanensis described above, sharing succulent peltate leaves, but differing in being glabrous, having fruit which are acute at the apex, and an erect succulent stem. The stem morphology is reminiscent of that found in B. wadei Merr. & Quisumb. ( Merrill & Quisumbing 1932) from coastal limestone karst in Palawan, and B. viscosa Aver. & H.Q.Nguyen ( Averyanov & Nguyen 2012) from crystalline limestone cliffs in central Laos; however both those species differ in having basifixed leaves.

Etymology

The epithet is derived from the name of the type locality, Gunung Batu Kudo in West Sumatra.

Type

SUMATRA: West Sumatra, Gunung Batu Kudo, 500 m, 19 Jun. 2011, Puglisi, Hughes, Girmansyah & Roki CP 67 (holo-: BO; iso-: E).

Additional material

SUMATRA: West Sumatra, Tanah Datar, Bukit Ngalau Pangian, 270–300 m, 6 Nov. 1993, Fitri, Hendrian et al. 35 ( ANDA , E).

Description

Succulent lithophytic herb growing on limestone cliffs. Stem succulent, erect, a modified rhizome, internodes c. 1 cm long. Stipules persistent, glabrous, 12–20 × 10–15 mm, lanceolate, strongly keeled, with a filiform extension 1.5–2.0 cm long. Leaves: petiole 10–12(–30) cm long, terete, glabrous; lamina suborbicular, peltate, subsymmetric, succulent, glabrous, 11–17 × 9–14 cm, upper surface light green, some darker colour forms have a brownish purple lamina, paler and green at the veins, venation radial, with 10–11 main veins, margin with recurved stiff teeth at the end of the veins, slightly indented given a pseudo-crenate appearance, teeth rounded-obtuse, c. 1.5 mm long. Inflorescences in terminal axils, total length c. 15 cm, cymose, branching around 4 times, c. 40-flowered, bisexual, protandrous; primary peduncle c. 10 cm long; lower bracts elliptic, c. 4 × 3 mm, entire, upper bracts minute, semi-persistent; peduncles and flowers minutely and densely puberulent when very young, becoming glabrous when mature. Male flowers: pedicel c. 2.5 cm long; tepals 4, small, white, outer tepals 2, suborbicular, 5–7 × 5 mm, inner tepals 2, elliptic, 5 × 3 mm; androecium globose, yellow, stamens c. 35, outer anthers subsessile, inner anthers on filaments about the same length as the anther, anthers 0.75 mm long, obtriangular, apex retuse, dehiscing through lateral slits about half the length of the anther. Female flowers: pedicel 2.5 cm long; ovary green, glabrous, total size including the wings 2 × 2.1 cm heartshaped, apex pointed, base retuse; capsule broadly ellipsoid, 11 × 9 mm, three locular, placentae entire; wings three, equal, rounded; tepals same as in the male flower; stigmas 3, yellow, Y-shaped, surface once spirally twisted. Fruit pendent on a thin 2.5 cm long pedicel, size and shape as for the ovary; apex obtuse.

Distribution and habitat

Known only from the type locality at Batu Kudo in West Sumatra ( Fig. 4 ), where it grows on bare vertical limestone cliffs at an altitude of 250– 400 m.

Conservation status

The vegetation at the base of the cliffs is disturbed and is being encroached by coffee plantations. The succulent leaves and stems mean the species is adapted to dryer conditions and seems to cope in the current conditions, although further disturbance to tree cover near to the cliffs should be discouraged. In combination with the very narrow distribution of B. kudoensis this means an IUCN category of Vulnerable is appropriate, under VUD2.

Figures

Fig. 4. Map of Sumatra showing the full known species distributions based on collection localities. Each point may represent more than one collection.

Fig. 11. Begonia kudoensis Girm. sp. nov. A. Habit (Gunung Batu Kudo, type collection Puglisi et al. CP67). B. Male flower, from cultivated plant in Bali Botanic Garden derived from CP67. C. Leaf lamina edge showing recurved teeth. D. Whole plants showing different colour forms. E. Female flower from cultivated plant in Bali Botanic Garden derived from CP67. F. Fruit on a pendulous pedicel (type collection Puglisi et al. CP67). C & D taken at the type locality. Scale bars on insets: B, C, E, F = 1 cm; D = 5 cm.