Begonia belagaensis S.Julia, Sandakania

Randi, Agusti, Ardi, Wisnu H., Girmansyah, Deden, Sitepu, Bina Swasta & Hughes, Mark, 2022, Three new species, one new record and an updated checklist of Begonia (Begoniaceae) from Kalimantan, Indonesia, Phytotaxa 533 (1), pp. 62-72 : 69-70

Begonia belagaensis S.Julia, Sandakania 20: 133 (2015).

Type: — MALAYSIA, Borneo, Sarawak, Belaga District, Sungai Chak ( Tributary of Sungai Murum ), 20 March 2014, Ling et al. BMHEP 3821 (holotype SAR). ( Fig. 4 ) .

Distribution:— Endemic to Borneo. In Sarawak recorded in Belaga District, and in Kalimantan this species is recorded from Samboja Forest Research (KHDTK Samboja), Tahura Bukit Soeharto, and Sepaku area, Penajam Paser Utara. All localities are near Balikpapan City. It is also recorded from one location in Sungai Lokang, Kapuas Hulu Regency, West Kalimantan.

Specimens examined:— INDONESIA, East Kalimantan, Kutai Kartanegara, Samboja , 0 o 59’00”S, 116 o 56’10”E, 45 m elev., 28 March 2020, Sitepu & Randi BSS 650 ( WAN) ; East Kalimantan, Penajam Paser Utara , 9 November 2019, Sitepu, BSS 602 ( WAN) ; East Kalimantan, PT. ITCI , Kenangan, Balikpapan , 50 m elev., 5 March 1991, Ambriansyah & Arifin AA94 ( WAN) .

Notes:— Although there are some differences between the specimens found in Kalimantan and the description in Julia et al. (2015), the specimens from Kalimantan have larger leaves (8–25 × 4–15 cm) and inflorescences bearing up to 6 pistillate flowers, the protologue describes smaller (12–12.5 × 11.5–12 cm) leaves, and inflorescences bearing 1–2 pistillate flowers). However comparison with images in Kiew et al. (2015) and correspondence with the collector of the type confirm that both are same species. Distinctive characters for the species shared between material from Sarawak and Kalimantan are large clumping habit, glabrous in all parts, leaf shape and texture, glandular bracts and bracteole margins, petioles deeply channeled above, and morphology and colour of male and female flowers. The records from Kalimantan are abundant at altitudes ranging from 30–220 m elev., and in Sarawak it is only recorded at 540–560 m elev.

Figures

FIGURE 4. Begonia belagaensis S.Julia. A. Plant habit in-situ; B. Leaves and inflorescence; C. Cross section of petioles; D. Adaxial leaf surface; E. Stipule; F, G. Side and top views of inflorescence with bracts; H. Front view of staminate flower with bracts and flower buds; I,J. Side and top views of pistillate flower; K. Side view of fruit; L. Cross sections of fruit. Scale bars: B: 10 cm, C: 5 mm, D: 10 cm, E: 5 mm, F: 10 cm, G: 2 cm, H–L: 10 mm. All photos by A. Randi Sitepu & Randi BSS 650 (WAN).