Introduction
The species of the genus Rhynchoglossum Blume (Gesneriaceae) are fleshy herbs with alternate leaf arrangements, asymmetrical leaf blades and unilateral racemose inflorescences. Rhynchoglossum comprises about 10–13 species distributed from India and southern China through SE Asia and Malesia to New Guinea, and from Mexico to Peru (Burtt, Reference Burtt1962; Mendum & Atkins, Reference Mendum and Atkins2004; Weber, Reference Weber, Kubitzki, Kadereit and Kadereit2004). Mendum & Atkins (Reference Mendum and Atkins2004) gave an estimate of 12 species of Rhynchoglossum of which only one species was said to occur in Sulawesi, namely R. obliquum Blume. This species is the most widespread in the genus and is distributed from India and southern China southwards through SE Asia and Malesia.
A new species of Rhynchoglossum has been identified as part of a revision of the genus for the Malesian region. The name Rhynchoglossum capsulare was noted on a specimen of this species by Ohwi but this name was never published. I do so here. Morphologically Rhynchoglossum capsulare is similar to R. obliquum with its small corolla and two fertile stamens but it differs in characters as laid out in the key below. Two species of Rhynchoglossum, R. obliquum and R. capsulare, are now known to occur in Sulawesi.
Henckelia Spreng. used to be one of the largest genera in the Gesneriaceae with c.180 species (Weber, Reference Weber, Kubitzki, Kadereit and Kadereit2004). It was distributed from India to New Guinea with a centre of diversity in Peninsular Malaysia (Kiew & Lim, Reference Kiew and Lim2011). The genus includes Henckelia kjellbergii B.L.Burtt which was described by Burtt (Reference Burtt1998) based on a specimen from SE Sulawesi (Kjellberg 1092).
Recent molecular analyses have shown that the species of Henckelia from India and Sri Lanka are distinct from those of southern Thailand and Malesia (Weber et al., Reference Weber, Middleton, Forrest, Kiew, Lim, Rafidah, Yao and Möller2011). The name Henckelia is retained for the Indian and Sri Lankan species whilst the southern Thailand and Malesian species now mostly belong to Codonoboea Ridl., with a smaller number in the resurrected genus Loxocarpus R.Br. (see Kiew & Lim, Reference Kiew and Lim2011; Weber et al., Reference Weber, Middleton, Forrest, Kiew, Lim, Rafidah, Yao and Möller2011). The necessary new combinations in Codonoboea have already been made for the species from Peninsular Malaysia (Kiew & Lim, Reference Kiew and Lim2011) but combinations are still necessary for the species from the rest of Malesia. Henckelia kjellbergii was described as belonging to Henckelia sect. Heteroboea (Benth.) A.Weber & B.L.Burtt (Burtt, Reference Burtt1998). The species of this section now belong in Codonoboea and the necessary new combination is made here.
Key to species of Rhynchoglossum in Sulawesi
1a. Leaf blade oblong; fruits elongate, half enclosed by persistent calyx R. capsulare
1b. Leaf blade ovate to elliptic; fruits ovoid, fully enclosed by persistent calyx R. obliquum
Species Description
Rhynchoglossum capsulare Ohwi ex Karton., sp. nov.Fig. 1.
Fig. 1.Rhynchoglossum capsulare Ohwi ex Karton. A, habit; B1, flower, B2, half-open flower; C, fruit [from Eyma 1572, holo BO].
Rhynchoglosso oblique Blume similis foliis oblongis, fructu elongatis calycis reliquiis parte dimidia inclusa differt. – Type: Indonesia, Celebes, Resident Menado, OA Poso, Maraowa N. side, 1200–1400 m, 5 viii 1937, Eyma 1572 (holo BO; iso A, K, L).
Fleshy erect annual herb, non-rhizomatous, c.19–40 cm high. Stem terete, glabrous, 2–5 mm diameter. Leaves alternate, exstipulate; lamina membranous, oblique, oblong, 3.5–11 cm long by 1.5–3 cm wide; base unequal, one side rounded, the other side cuneate; apex acuminate, tip 0.5 cm long; margin entire; lamina surface glabrous adaxially, puberulous abaxially, pale green; petiole glabrous, terete, 0.5–2 cm long. Inflorescences racemose, slender, terminal and axillary, 8–9 cm long, up to 11-flowered; main axes terete, glabrous; peduncles 2–5 cm long; bracts absent; pedicels puberulous, 0.5–1 mm long; bracteoles in the middle of the pedicels, linear, glabrous, c.0.5 mm long. Flowers 10–14 mm long. Calyx tube campanulate, glabrous to puberulous, 3–5 mm long by 1–2 mm wide, formed into a tube at the base for 1.5–3 mm; calyx lobes triangular, acute, 5-merous, 1.5–2 mm long. Corolla tubular, glabrous outside and inside, 1–1.8 cm long, whitish blue to dark violet; tube 8 mm long; limb 2-lipped, 8–10 mm long; adaxial smaller than abaxial, 2-lobed, 2–4 mm long; abaxial linguiform, slightly 3-lobed, 8–10 mm long, apex rounded. Stamens 2, coherent, glabrous; anthers ovoid, 2-thecate, parallel, opening by longitudinal slits, basifixed, 0.5 mm diameter; filaments terete, 2–4 mm long, inserted in the middle of tube on adaxial side. Ovary oblong, glabrous, 1-locular, 1–3 mm long; style terete, glabrous, 1–1.2 cm long; stigma capitate, 1 mm diameter. Fruits capsule-like, elongate, 4–10 mm long by 2–3 mm wide, glabrous; stalk puberulous, 2–3 mm long, half enclosed by the persistent calyx; persistent calyx 3–7 mm long; style remnant up to 5–6 mm long. Seeds minute, ellipsoid, tessellate, 0.3–0.4 mm long.
Distribution. Endemic to Sulawesi (Fig. 2).
Distribution map of Rhynchoglossum capsulare Ohwi ex Karton. (▪) and the Sulawesi distribution of Codonoboea kjellbergii (B.L.Burtt) Karton. (•).
Habitat. In open areas in mountain forest at 1200–1400 m altitude.
Etymology. The specific epithet refers to the appearance of the fruit.
Additional specimens examined. SE Sulawesi, B. Porema, 1400 m, 27 x 1929, Kjellberg 2663 (BO).
Rhynchoglossum capsulare is the only species of the genus with a capsule-like fruit. In addition there are no wings on the persistent calyx and the calyx does not fully enclose the fruit as is common elsewhere in the genus. The description is based only on herbarium specimens due to the absence of living material.
New Combination
Codonoboea kjellbergii (B.L.Burtt) Karton., comb. nov. – Henckelia kjellbergii B.L.Burtt, Beitr. Biol. Pflanzen 70: 378 (1998). – Type: Indonesia, Celebes, Boeloe Watoewila, 1500 m, 24 iii 1929, Kjellberg 1092 (holo S n.v.; iso BO).
Distribution. Sulawesi, Moluccas (Ambon and Seram), New Guinea (Fig. 2).
Additional Sulawesi specimens examined. Southeast Sulawesi: Edge of Kendari–Kolaka Road km 22, near Iwoi Mohalu river, Horodopi, Subdist. Mowewe, Distr. Kolaka, 300 m, 23 v 2008, Kartonegoro 279 (BO, E, K, L); G. Kumapodahu, Mt. Watuwila, Sanggona, Subdistr. Uluiwoi, Distr. Kolaka, 300 m, 14 v 2008, Kartonegoro 235 (BO, E, K, L); Kendari–Pohara, 50 m, 7 iii 1929, Kjellberg 730 (BO); Buton Island, Membulu, 1910, Elbert 3177 (BO, L); Rumbia, 1909, Elbert 3156 (BO, L). South Sulawesi: Balo-Balo Mt., Kwoi Toro, near Wasoponda, between Soroako and Malili, 800 m, Hennipman 6135 (BO, K, L); Todjamboe, 800 m, 3 vii 1929, Kjellberg 1882 (BO); Preho, 600 m, x 1929, Kjellberg 4048 (BO); G. Taponga, viii 1913, Rachmat 458 (BO); G. Latoepa, xi 1913, Rachmat 862 (BO). Central Sulawesi: Kolonedale, between camp III and Tompantette, 10 x 1938, Eyma 3981 (BO); Poso, between Pape and Pendolo, 26 x 1938, Eyma 4070 (BO).
Codonoboea kjellbergii is the only species of the genus in eastern Malesia and is found in Sulawesi, the Moluccas (Ambon and Seram) and New Guinea. It is similar to Codonoboea crinita (Jack) C.L.Lim from Sumatra, Peninsular Malaysia and Borneo. Both species have oblong-lanceolate and pubescent leaf blades but Codonoboea crinita is larger in habit and has larger leaves and flowers.
Acknowledgements
The author would like to give special thanks to D. J. Middleton (E) for his advice and for his comments on the manuscript; to W. S. Hoover (NETC) for the Indonesian Biodiversity Exploration and Taxonomy Project (IBETP) Grant 2008 for his work on Sulawesi Gesneriaceae; and to the Director of the Singapore Botanic Gardens for a Fellowship Grant in 2010 to examine specimens of Gesneriaceae in SING. Thanks also to Anne Kusumawaty for the illustration.
