Cyrtandra hypogaea Koord., Meded. Lands Plantentuin

Atkins, H. J. & Kartonegoro, A., 2021, A TAXONOMIC REVISION OF CYRTANDRA (GESNERIACEAE) IN SULAWESI, INDONESIA, Edinburgh Journal of Botany 78 (364), pp. 1-122 : 56-59

16. Cyrtandra hypogaea Koord., Meded. Lands Plantentuin 19: 628 (1898).

– Type: Indonesia, Celebes [Sulawesi], Mt Lolombulan , 9 iv 1897, Koorders 17190β (lectotype BO, designated here; isolectotype L). Figure 30 .

Branching herb or shrub to 2 m in height, rarely epiphytic (de Vogel 2649). Stems striate, subglabrous, hairy on young growth, woody at base. Leaves opposite; both members of a pair well developed but somewhat unequal in size; petiole 10–35 mm long, hairy to densely hairy; blades (5–)10–25 × (1.5–) 3.5–6 cm, usually narrow obovate, sometimes narrow oblong or oblanceolate, base acute, briefly decurrent, slightly asymmetrical, margin serrulate to serrate, apex acuminate; 5–7(–8) pairs of lateral veins, curving upwards and running out to margin, sometimes with short lateral veins running out to adjacent teeth, sparsely hairy above, hairy below, more densely so on midrib, veins and margins. Inflorescences trailing from base of main plant; trailing inflorescence axis 2–3 mm in diameter, up to 2 m long, glabrous, usually appearing ‘notched’ from the remnants of old bracts; bracts 3–5 × 1–2 mm, ovate, acuminate at apex, hairy, not connate, caducous. Calyx purple or reddish, 6–10 mm long, evenly 5-lobed or bilabiate with three lobes joined to halfway, lobes linear, 6–8 mm or divided briefly at apex, hairy externally. Corolla white flushed pink with deep-red guidelines and light yellow or orange in the throat or, rarely, bright red with (or without) yellow in the throat, 8–15 mm long, more or less parallel-sided, widening at mouth, lobes not recurved, lobes 3–4 × 2–3 mm, hairy externally. Stamens with filaments 1–2 mm long, attached 4–7 mm from base of corolla; anthers 1 mm long, connected at apices before dehiscence; staminodes 3, laterals c. 1 mm long, central c. 0.5 mm long. Gynoecium 4–7(–10) mm long; disc unilateral with undulate to lobed margin, 1–2 mm long, glabrous; ovary subglabrous to sparsely hairy; style eglandular hairy for whole length; stigma bilobed, lobes vertical, 1–2 mm long, densely glandular on inner surface of lobes. Fruits ovoid to narrow ovoid, green when unripe, sometimes recorded as turning reddish, glabrous, distinctively tessellate when dried, 9–12(–15) × 2–5 mm, calyx and base of style usually persistent.

Distribution. North Sulawesi, Gorontalo, Central Sulawesi, West Sulawesi, South Sulawesi, Southeast Sulawesi (see Figure 31 ).

Habitat and ecology. Lowland, Hill and Upland Forest at an altitude of 50–1290 m.

Etymology. The epithet of this species refers to the position of the flowers near the ground ( Koorders, 1898).

Proposed IUCN conservation category. The EOO of Cyrtandra hypogaea is 173,191 km 2 and the AOO is 112 km 2, based on a 2 × 2 km grid cell size, under the B criteria ( Bachman et al., 2011). This is one of the most common and widespread species on the island, collected in all of the six provinces in Sulawesi and over a wide altitudinal range, and for this reason is considered to be of Least Concern (LC).

Additional specimens examined. INDONESIA. North Sulawesi. Bolaang Mongondow: Kasingolan River, 30 xi 2016, Barber, Atkins, Kartonegoro & Kinho BAKK17 (BO, E); Mt London, 31 xi 2016, Barber, Atkins, Kartonegoro & Kinho BAKK30 (BO, E); Dumoga Bone [Bogani Nani Wartabone] National Park, 28 iii 1985, de Vogel & Vermeulen 6786 (E, L); North Minahasa: South part of Wiau forest reserve, base of Mt Klabat, 1 xi 1973, de Vogel 2649 (BO, CANB); Tomohon: Wagio crater, Mt Mahawu, 4 vii 1956, Forman 393 (BO, L); Mt Mahawu, 15 ii 2009, Girmansyah 1257 (BO).

Gorontalo. Bone Bolango: Route along the Olama River to Mt Gambuta, 9 iv 2002, Scott 02-42, grown at RBGE as accession 20021875A, vouchered as Atkins 46 (E).

Central Sulawesi. Banggai: inland from Batui, 17 x 1989, Coode 5983 (A, BO, K, L, SING); Bunta Subdistrict, Sumber Agung, Mt Hek, 26 ii 2004, Hendrian, Newman, Scott, Saleh & Supriadi 900 (E); Luwuk District, Bunta Subdistrict, Sumber Agung, Mt Hek, 26 ii 2004, Scott 04-329, grown at RBGE as accession 20040647A, vouchered as Scott 449 (E); Parigi Moutong: Pangi Binangga, Uwe Lutu, CA, 20 vii 2018, Ardi WI209 (KRB); Between Palu and Parigi, 35 km from Palu, 7 iv 1975, Meijer 9342 (BO, L); Poso: Danau Poso, Tentena-bancea road divide, 2 viii 2018, Ardi WI277 (KRB); Pass between Lake Poso and Wotu, 2 iii 2000, Mendum, Argent & Hendrian 00220 (BO, E); Sigi: Mt Nokilalaki, track to shelter 2, 24 vii 2018, Ardi WI222 (KRB); ibid., 24 vii 2018, Ardi WI230 (KRB); Upper Sopu River, E. end of Sopu Valley, 5 v 1979, van Balgooy 3501 (L); Danau Tambing, 23 v 1979, van Balgooy 3434 (BO, E, L); Mt Nokilalaki, 10 vii 1939, Bloembergen 4029 (BO, L); Lore Lindu National Park, Ponoh, 3 km NE of Toro Village, 17 xii 2007, Cicuzza 620 (E); Lore Lindu, Mt Nokilalaki, 6 iii 2008, Cicuzza 793 (E); Lore Lindu National Park, Ponoh, 3 km NE of Toro Village, 10 iv 2008, Cicuzza 1016 (E); Sopu Valley, c. 80 km s. of Palu, 6 v 1979, Hennipman 5621 (BO, E); W of Tongoa, 6 iii 1981, Johansson, Nybom & Riebe 195 (L); Mt Roroka Timbu, 11 v 1979, de Vogel 5296 (L); ibid., 11 v 1979, de Vogel 5315 (L); Sopu valley c. 80 km SSE of Palu, 26 v 1979, de Vogel 5578 (BO, L); Toli-Toli: Mt Dako, Teluk Bone, Lakatan, 24 iii 1985, Ramlanto & Zainal Fanani 513 (BO).

West Sulawesi. Mamasa: Mt Gandang Dewata, 20 iv 2016, Kartonegoro, Ardiyani, Santoso, Wardani ARK904 (BO, E).

South Sulawesi. East Luwu: Mt Wawonseru, SW of Soroako, 3 vi 1979, Hennipman 5994 (BO, E); Kawata, 18 ix 1929, Kjellberg 2334 (BO, S).

Southeast Sulawesi. Selewar, Preko, 5 x 1929, Kjellberg 2498 (BO, S); North Kolaka: Bulu Porema, 27 x 1929, Kjellberg 2664 (BO, S); Rante Angin subdistrict, Tinukari village, 30 vi 2011, Widjaja, Sujadi, Santoso & Hapid EAW9713 (BO); Tinukari village, 30 vi 2011, Widjaja, Sujadi, Santoso & Hapid EAW9717 (BO).

Cyrtandra hypogaea can be easily distinguished from other species on Sulawesi with trailing inflorescences by a thicker, and usually more notched, inflorescence axis 2–3 mm in diameter, smaller flowers, and a unilateral disc. The fruits also have a distinct, tessellate appearance when they are dried.

Koorders did not specify a type when he described this species. Therefore, the most complete of Koorders own collections, Koorders 17190β in the herbarium in Bogor (BO), annotated by him with the name Cyrtandra hypogaea and with an illustration attached, has been selected as the lectotype.

There are three collections from the Lore Lindu area of Central Sulawesi, namely Ardi WI230, van Balgooy 3434 and de Vogel 5315, which are recorded as having a red corolla, sometimes with yellow markings on the lower lobes. The phenomenon of colour variation, although very rare in Cyrtandra , has been seen in C. splendens C.B.Clarke from Borneo. In that case, the corolla, usually white or cream-coloured with a large crimson patch on each lobe, was found in one or two populations to have a wholly red corolla ( Burtt, 1990). These red-flowered specimens fall within the distribution range of Cyrtandra hypogaea . The collections also bear some resemblance, particularly in the striking red corolla colour, to the closely related Cyrtandra rantemarioensis from the Latimojong Range in South Sulawesi but can be separated from that species geographically and also by ovary indumentum, leaf decurrence and fruit shape. Further collections are required to confirm the status of these collections, but for now they are treated as Cyrtandra hypogaea .

Figures

Figure 30. Cyrtandra hypogaea. a, Habit; b, front view of flowers; c, side view of flowers; d, trailing inflorescence. Photographs: Sadie Barber. Specimen: Barber et al. BAKK30.

Figure 31. Distribution of Cyrtandra hypogaea (black triangles) and C. jellesmanii (red circles).