Begonia harauensis 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 : 14-15

Begonia harauensis Girm. sp. nov. § Petermannia

urn:lsid:ipni.org:names:77151641-1

Figs 2 , 6

Diagnosis

The inflorescence and habit of B. harauensis most closely resembles that of B. laruei M.Hughes ( Hughes et al. 2009) from North Sumatra and Aceh, but it is a smaller species (c. 50 cm tall, not to c. 100 cm tall) with narrower leaves (2–5.5 cm wide, not 3.5–10 cm wide) without lobes, which are so asymmetric as to almost displace the point of petiole attachment to the side of the leaf. The shrinkage that occurs upon drying accentuates this, giving the leaves a tear-drop shape.

Etymology

The epithet refers to the distribution of the species, Lembah Harau in West Sumatra near Payakumbuh.

Type

SUMATRA: West Sumatra, Lembah Harau Nature Reserve, 500 m, 24 Jul. 2009, Hughes & Rubite MH 1557 (holo-: BO; iso-: E).

Additional material

SUMATRA: West Sumatra, Kepala Banda, ANDA collectors 4 ( ANDA ); ibid., 22 Oct. 1989, ANDA collectors 106 ( ANDA ); ibid., 22 Oct. 1989, ANDA collectors 142 ( ANDA ); ibid., 3 Apr. 1988, Darmansyah 33 ( ANDA ); ibid., 10Apr. 1988, Lani & Arnov 48 ( ANDA ); ibid., 10 Nov. 1984, Meriyatmi, E. 12 ( ANDA ); ibid., 3 Apr. 1988, Ranti 12 ( ANDA ); ibid., 3 Apr. 1988, Suluh, B. 41 ( ANDA ); Lembah Harau Nature Reserve, 3 Apr. 1988, Heravela 22 ( ANDA ); ibid., 27 Aug. 1983, Hotta, M. & et. al. 335 ( ANDA ); ibid., 24 Jul. 2009, Hughes, M. & Rubite, R. MH 1557 ( E); ibid., 23 Jul. 2009, Hughes, M. & Taufiq, A. MH 1556 ( E); Lembah Harau Nature Reserve, Sarasah Bonta, 14 Nov. 1992, ANDA collectors 9 ( ANDA ); ibid., 27 Aug. 1983, ANDA collectors 4 R ( ANDA ); ibid., 2 Apr. 1988, ANDA collectors 11 ( ANDA ); ibid., 2 Mar. 2001, ANDA collectors 29 ( ANDA ); ibid., 14 Nov. 1992, ANDA collectors 49 ( ANDA ); ibid., Dec. 1994, ANDA collectors 51 ( ANDA ); ibid., 15 Nov. 1992, ANDA collectors 63 ( ANDA ); ibid., 10 Dec. 1994, ANDA collectors 67 ( ANDA ); ibid., 11 Dec. 1994, ANDA collectors 92 ( ANDA ); ibid., 11 Dec. 1994, ANDA collectors 95 ( ANDA ); ibid., 11 Dec. 1994, ANDA collectors 99 ( ANDA ); ibid., 10 Dec. 1984, ANDA collectors 156 ( ANDA ); ibid., 11 Dec. 1994, Fit, Nung, Eci, Tis & Martin 78 ( ANDA ); ibid., 10 Dec. 1994, Irya, Eva, Del, Titin & Yenny 48 ( ANDA ); ibid., 27 Aug. 1983, Nelly, Delli, Harry & Eka 83 ( ANDA ); ibid., 10 Dec. 1994, On, Fera, Yat, Tin & Rina , S. 3 ( ANDA ); ibid., 11 Dec. 1994, Pions, Eka, Wasti, Dewi & Len 68 ( ANDA ); West Sumatra, Pajakumbuh, Taram, 3 Apr. 1988, Johanes, R. 23 ( ANDA ); ibid., 23 Aug. 1956, Meijer, W. 6843 ( L); River Tjampo, Aug. 1957, Ismail 47 ( L).

Description

Erect caulescent herb to c. 50cm tall; stem erect, glabrous, red, internodes 2–8 cm long. Stipules deciduous, glabrous, lanceolate, 8 × 4 mm, apex acute. Leaves: petiole 1.5–4 cm, terete, minutely puberulent; lamina lanceolate, glabrous, strongly asymmetric, basifixed, base shallowly cordate to sub truncate, apex long acuminate, 8–16 × 2–5.5 cm, uniform pale green, midrib 7–13 cm, venation palmatepinnate, margin subentire to sparsely denticulate. Inflorescences terminal, up to 22 cm in total length, a raceme of cymes, glabrous, with 2– 4 female flowers at the base, up to c. 50 male flowers distally, protogynous; primary peduncle 3–7 cm long; bracts deciduous, elliptic, glabrous, entire, c. 7 × 5 mm, apex rounded. Male flowers: pedicel c. 5 mm long, glabrous; tepals 4, pale pink, outer 2 tepals orbicular, c. 7 × 6 mm, glabrous or minutely puberulent adaxially, inner 2 elliptic obovate, c. 5 × 3 mm; androecium pale yellow, symmetric, globose, stamens c. 35, filaments subequal, c. 0.5 mm long, arranged on a short 0.5 mm long column, anthers oblong, c. 0.5 mm, apex retuse, hooded, dehiscing through slits about half the length of the anther, slits placed laterally. Female flowers: pedicel 2–5 mm long, glabrous; ovary green, glabrous, total size including wings 17 × 14; capsule ellipsoid, 3-locular, placentae bifid; wings three, equal, 15 × 4 mm; tepals 5, pale pink, outer 2 ovate, c. 7 × 5 mm, inner 3 elliptic, smaller, c. 7 × 4 mm; styles 3, yellow, c. 4 mm long, bifid, U-shaped, stigmatic band once spirally twisted. Fruit usually in pairs, on a stiff 5 mm long pedicel, total size 17 × 15 mm; apex truncate.

Distribution and habitat

Endemic to Lembah Harau and immediate surroundings ( Fig. 2 ), where it grows on stream banks and at the base of sandstone cliffs.

Conservation status

Begonia harauensis is assessed as Least Concern due to its distribution overlapping the Lembah Harau Protection Forest, and the large number of specimens in ANDA giving an indication of a quite common, if locally endemic, plant.

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. 6. Begonia harauensis Girm. sp. nov. A. Habit (Lembah Harau Nature Reserve, Hughes, M. & Taufiq, A. MH 1556). B. Male inflorescence. C. Male flower. D. Pair of female flowers showing ovary. E. Unripe fruit. Insets from plant cultivated in Bogor Botanical Garden (accession number B200608257/ JS 436, derived from material collected in Lembah Harau). Scale bars on insets = 1 cm.