Cyrtandra albiflora Karton. & 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 : 17-19

1. Cyrtandra albiflora Karton. & H.J.Atkins , Edinburgh J. Bot. 75(2): 174 (2018).

– Type: Indonesia, Sulawesi, Central Sulawesi, Sumber Agung, Sungai Spa , 92 m, 24 ii 2004, Hendrian, Newman, Scott, Saleh, & Supriadi 848 (holotype E, isotype BO). Figure 11 .

Shrub to 60 cm in height. Stems striate, densely villose hairy on young growth, hairs up to 3 mm long, indumentum less dense on older growth. Leaves opposite, subequal (with occasional whorl of smaller leaves on cultivated plants); petiole c. 2 cm long, hairy; blades 17–22.5 × 5.1–7.7 cm, narrow oblong, base decurrent, only very narrowly winged near base, margin serrulate, apex acuminate; 9–11 pairs of lateral veins and reticulate tertiary venation, light green and hairy above, appearing whitish and hairy below, most densely so on midrib and veins. Inflorescences axillary, sessile, with c.8–10 flowers at various stages of development; bracts green, caducous, 10–11 × 5 mm, linear-lanceolate, hairy on both surfaces, most densely so along margins; bracteoles 6–8 mm long, linear, hairy internally and along margins; pedicels 2–3 mm long, densely hairy. Calyx tubular, green, 5–6 mm long, lower lip 2-lobed, lobes short-acuminate, c. 3 mm long, upper lip divided very briefly at apex, densely hairy externally. Corolla white, 10–12 mm long, widening gradually to mouth, mouth oblique, upper lobes rounded erect to slightly recurved, 1.5 × 2 mm, lower and lateral lobes more elongate, spreading to slightly recurved, 3 × 2.5 mm, hairy externally and with glandular hairs internally, on lobes and in mouth. Stamens with filaments c. 1 mm long, attached 5–6 mm from base of corolla, glabrous; anthers c. 1 mm long, glabrous, cohering at apices; staminodes 3, all less than 0.2 mm long. Gynoecium 5.5–6 mm long; disc cupular with undulate margin, 1 mm long, glabrous; ovary glabrous; style glandular hairy; stigma slightly bilobed, lobes small and held upright. Fruits ovoid, drying dark brown, glabrous, verrucose, 5–6 × 2–3 mm, base of style and calyx persistent.

Distribution. Central Sulawesi (see Figure 14 ).

Habitat and ecology. Disturbed lowland forest in a limestone area at an altitude of 92– 220 m.

Etymology. This species is named for its white flowers ( Kartonegoro et al., 2018).

Proposed IUCN conservation category. Cyrtandra albiflora is known from a single mountain from which two collections were made on the same trip in 2004 at altitudes of 92 and 220 m. The lack of specimens precludes estimations of EOO, but the species has an AOO of 8 km 2 ( Bachman et al., 2011).

According to Cannon et al. (2007), lowland forest is one of the most threatened habitats on the island, and there are no protected areas in this part of Sulawesi (UNEP-WCMC & IUCN, 2019). Until more intensive botanical exploration can be carried out in this area, it is assumed that this species is restricted to the type locality. There is some intact forest on the mountain at higher altitudes, but signs of habitat degradation are present at lower altitudes (UNEP-WCMC & IUCN, 2019). Because Cyrtandra albiflora is known only from a population on a single mountain in an area without protection and in a habitat that is known to be threatened ( Cannon et al., 2007), it is assessed as Critically Endangered (CR), B2ab(iii).

Additional specimen examined. INDONESIA. Central Sulawesi. Banggai: Mt Hek, Sungai Spa , 24 ii 2004, Scott, S. 04-307, grown on at the Royal Botanic Garden Edinburgh (RBGE) as accession 20040645A, vouchered as Scott 509 (E) .

Cyrtandra albiflora is similar to C. hendrianii , also from Mount Hek, in being a shrub with subequal, decurrent leaves and many-flowered axillary inflorescences. It can be distinguished, however, by its white corolla (versus pink corolla), green calyx (versus red calyx), densely hairy stems and leaves (versus more or less glabrous stems and leaves), and linear-lanceolate bracts 10–11 mm long (versus oblong-lanceolate bracts 25–35 mm long).

Figures

Figure 11. Cyrtandra albiflora. a, Fruit and calyx; b, gynoecium including disc; c, habit; d, opened corolla, showing position of stamens and staminodes; e, anthers; f, opened calyx, showing inner surface; g, side view of corolla; h, detail of upper leaf surface; i, bracts and bracteoles. Drawn by Claire Banks from Hendrian et al. 848. Reproduced from Kartonegoro et al. (2018) with the permission of the Trustees of the Royal Botanic Garden Edinburgh.

Figure 14. Distribution of Cyrtandra albiflora (black triangle), C. balgooyi (black squares) and C. boliohutensis (red circles).