Cyrtandra serratifolia H.J.Atkins

Atkins, H. J. & Kartonegoro, A., 2021, A TAXONOMIC REVISION OF CYRTANDRA (GESNERIACEAE) IN SULAWESI, INDONESIA, Edinburgh Journal of Botany 78 (364), pp. 1-122 : 102-105

34. Cyrtandra serratifolia H.J.Atkins , Edinburgh J. Bot. 60(3): 313 (2004).

– Type: Indonesia, Sulawesi, North Sulawesi, Bolaang Mongondow, 16 iv 1985, de Vogel & Vermeulen 7202 (holotype BO; isotypes E, K, L). Figures 52 , 53 .

Erect or creeping shrub to 30 cm in height. Stems longitudinally striate, hairy, more densely so when young. Leaves opposite, sometimes in threes; all well developed but somewhat unequal in size; petiole 1–4 mm long, hairy to densely hairy; blades 0.5–3 × 0.4–1.2 cm, wide elliptic, base obtuse, margin serrate, apex rounded to short acuminate; 3 or 4 pairs of lateral veins, occasionally with short veins running to adjacent teeth, sparsely hairy, more densely so on midrib and margins above and midrib and veins below. Inflorescences axillary, sessile, 1- or 2-flowered; bracts 3–5 × 1 mm, linear hairy; pedicels 4–5 mm long, hairy. Calyx green, 7–9 mm long, with 5 equal subulate lobes, 5–6 mm long, hairy externally, most densely so at median line of lobes and at their tips. Corolla pink or red, 20–26 mm long, funnel-shaped, slightly arcuate, lobes rounded, upper lobes 5–6 × 7–8 mm, lower lobes 6–7 × 5–6 mm, hairy externally. Stamens with filaments c. 2 mm long, attached 12–14 mm from base of corolla, filaments with some sessile glands; anthers c. 1.5 mm long, cohering at apices before dehiscence; staminodes 3, all less than 1 mm long. Gynoecium 9–13 mm long; disc cupular, undulate, c. 1 mm long, glabrous; ovary subglabrous at base becoming glandular hairy towards style; style glandular hairy; stigma bilobed, lobes c. 3 mm across. Fruits ovoid, c.10 × 5 mm (possibly immature), subglabrous but with glandular hairs at base of persistent style; calyx persistent.

Distribution. North Sulawesi and Gorontalo (see Figure 55 ).

Habitat and ecology. Upland and montane forest at an altitude of 1300–1800 m.

Etymology. This species is named for its distinctive serrate leaves ( Atkins, 2004).

Proposed IUCN conservation category. The EOO of Cyrtandra serratifolia is 1811 km 2 and the AOO is 20 km 2, based on a 2 × 2 km grid cell size, under the B criteria ( Bachman et al., 2011). The collections are from relatively high-altitude forest, which is less threatened in Sulawesi ( Cannon et al., 2007) than the lowland areas, and from within the protected areas of Mount Ambang Nature Reserve and Bogani Nani Wartabone National Park (UNEP-WCMC & IUCN, 2019). Because of its distribution entirely within protected areas, a category of Least Concern (LC) is given for this species.

Additional specimens examined. INDONESIA. North Sulawesi. Bolaang Mongondow: viii 1917, Kaudern 184 ( BO) ; Dumoga Bone National Park [Bogani Nani Wartabone], 26 ix 1991, Milliken 1064 ( E, L) ; East Bolaang Mongondow: Mt Ambang Nature Reserve , 2 xi 2016, Barber, Atkins, Kartonegoro & Kinho BAKK44 ( BO, E) ; ibid., 3 xi 2016, Barber, Atkins, Kartonegoro & Kinho BAKK54 ( BO, E) .

Gorontalo. Bone Bolango: Mt Gambuta, 12 iv 2002, Atkins et al. 93 (BO, E); ibid., 12 iv 2002, Scott 02-82, grown on at RBGE as accession 20021210A, vouchered as Atkins 10 (E); ibid., 12 iv 2002, Scott 02-82, grown on at RBGE as accession 20021210A, vouchered as Cubey & Scott 255 (E).

Cyrtandra serratifolia differs from any other yet seen from Sulawesi in its tiny serrate leaves and low scrambling habit. It does, however, share this habit and leaf shape with Cyrtandra tarsodes B.L.Burtt from very high–altitude areas in New Guinea and C. auriculata C.B.Clarke and C. zamboengensis Merr. from the Philippines. There seems to be some variation in corolla colour, with the recent collections from Mount Ambang having much brighter red corollas than those from Mount Gambuta, which are a paler, slightly metallic pink. These differences were observed both in the wild populations and in cultivation.

Figures

Figure 52. Cyrtandra serratifolia. a, Habit; b, opened corolla, showing position of stamens and staminodes; c, opened calyx, showing inner surface; d, gynoecium including disc. Drawn by Christina Oliver from Atkins et al. 93. Reproduced from Atkins (2004) with the permission of the Trustees of the Royal Botanic Garden Edinburgh.

Figure 53. Cyrtandra serratifolia. a, Side view of flower; b, front view of flower; c, habit. Photographs: Sadie Barber. Specimen: Barber et al. BAKK54.

Figure 55. Distribution of Cyrtandra serratifolia (red diamonds), C. spectabilis (black circle) and C. spicata (black triangles).