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Begonia araneumoides Ardi & Girm., Begonia batuphila Girm., Begonia hijauvenia Girm., Ardi & M.Hughes, Begonia mursalaensis Girm., M.Hughes & Ardi., Begonia panjangfolia Girm., Ardi & M.Hughes, Begonia perunggufolia M.Hughes & Girm., in Girmansyah, Hughes, Sulistijorini, et al., 2022. |
Abstract
Six new species of Begonia sect. Jackia from Sumatra are described and illustrated: B. araneumoides, B. batuphila, B. hijauvenia, B. mursalaensis, B. panjangfolia, and B. perunggufolia. All morphological characters and measurements were observed from living plants in the Bogor Botanical Gardens greenhouse or the wild. Using IUCN criteria, 4 species are considered to be Data Deficient, 1 Vulnerable, and 1 Least Concern.
Keyword: Begonia araneumoides, B. batuphila, B. hijauvenia, B. mursalaensis, B. panjangfolia, B. perunggufolia
Begonia araneumoides Ardi & Girm., sp. nov.
Diagnosis: Begonia araneumoides most closely resembles B. droopiae (Ardi and Hughes, 2010) from Solok Ambah, West Sumatra in having strongly asymmetric leaves which are rugulose with a crenate and fringed margin, but it can be differentiated by its mix of basifixed and eccentrically peltate leaves (vs. purely basifixed); smaller male flower outer tepals 5‒7 × 6 mm (vs. 11–17 × 6–7 mm), and an ellipsoid capsule (excluding the wings) (vs. broadly ellipsoid to subglobose).
Distribution and habitat: Endemic to Sumatra, West Sumatra, Limapuluh Kota Regency, in lowland forest.
Etymology: Latin (araneum: spiderweb; oides: resembling), referring to the pattern of tertiary veins which are arranged like a spiderweb.
Begonia batuphila Girm., sp. nov.
Diagnosis: Begonia batuphila resembles Begonia inversa Irmsch. (Irmscher 1953) in its diminutive habit but differs in having suborbicular-ovate leaves (vs. obovate-cuneate) which are widest at the middle (vs. the apical third of the lamina) and larger male flowers with orbicular tepals 1–1.4 × 0.8–1 cm, (vs. oval tepals 7 × 4 mm).
Distribution and habitat: Sumatra, West Sumatra, on the coast near Padang, and in the hills surrounding Payakumbuh and Sijungjung, growing on damp, shaded cliff faces or large boulders below the tree canopy at 50– 800 m altitude. Frequently found on limestone.
Etymology: Derived from the Indonesia word for rock (batu), referring to the lithophytic habit of this species.
Begonia hijauvenia Girm., Ardi & M.Hughes, sp. nov.
Diagnosis: Begonia hijauvenia is similar in habit and leaf shape to Begonia raoensis M.Hughes (Hughes et al. 2015a) but differs in having a purple-brownish lamina with pale green veins (vs. uniform green) with a broadly scalloped margin (not subentire), longer peduncles up to 40 cm (vs. c. 20 cm) which are white pilose (vs. red pilose with fleshy red hairs at the petiole apex) and 115 stamens (vs. c. 50).
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Distribution and habitat: Endemic to Sumatra, North Sumatra, in lowland forest.
Etymology: Derived from the Indonesian word for green (hijau), referring to the green veins of the leaves.
Begonia mursalaensis Girm., M.Hughes & Ardi., sp. nov.
Diagnosis: Begonia mursalaensis is most similar to B. raoensis M.Hughes (Hughes et al., 2015a) in habit, mature leaf colour, and red-pilose petioles with hairs denser at the apex, but differs in having leaf lamina ovate to broadly ovate (vs. suborbicular), larger male flower tepals 12–15 × 11–12 mm (vs. c. 8 × 7 mm) with more stamens (122 vs. 50), fruit which are on a ca. 10 mm stiff recurved pedicel (not pendent on a ca. 20 mm hair-like pedicel) and more elongate triangular fruit wings (vs. rounded triangular). Also similar to B. stictopoda in habit and leaf shape but differs in having petioles which are red-pilose (vs. white sparsely tomentose) and more elongate triangular fruit wings (vs. rounded fruit wings).
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Distribution and habitat: Endemic to Sumatra, North Sumatra, Mursala Island, growing on the rocky banks of streams.
Etymology: The epithet refers to the name of Mursala Island in North Sumatra, the type locality of the species.
Begonia panjangfolia Girm., Ardi & M.Hughes, sp. nov.
Diagnosis: The combination of dimorphic stipules and elongate elliptic-lanceolate leaves differentiates Begonia panjangfolia differentiate this species from all other species in Begonia sect. Jackia.
Distribution and habitat: Endemic to Sumatra, West Sumatra, Pasaman, Batang Landu. On the banks of the Batang Lindu river at c. 150 m altitude.
Etymology: Derived from the Indonesia word panjang, meaning long, referring to the quite elongate leaf shape which is unique in Begonia sect. Jackia in Sumatra.
Begonia perunggufolia M.Hughes & Girm., sp. nov.
Diagnosis: Begonia perunggufolia is most similar to B. kemumuensis M.Hughes (Hughes, 2015) in habit, but differs in having an unlobed leaf margin (vs. with 2–6 pointed short lobes), upper leaf surface bright green along the primary veins and brownish green in between (vs. uniform green), male flower tepals broadly ovateorbicular (vs. ovate), and a globose androecium with c. 50 anthers (vs. globose-cylindrical with c. 100 anthers).
Distribution and habitat: Endemic to Sumatra, North Sumatra, in lowland forest.
Etymology: Derived from the Indonesian word for bronze (perunggu), referring to the bronze colour on the leaves.
Deden Girmansyah, Mark Hughes, Sulistijorini, Rugayah, Wisnu H. Ardi and Tatik Chikmawati. 2022. Six New Species of Begonia (Sect. Jackia, Begoniaceae) from Sumatra, Indonesia. Taiwania. 67(1); 97-109. taiwania.NTU.edu.tw/abstract.php?type=abstract&id=1814
