Sapindus motu-koita A. R. Franck, sp. nov.
Creators: name: Franck, Alan R.
Publisher: name: Zenodo
Year: 2024
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Magnoliopsida
Sapindales
Sapindaceae
Sapindus
Sapindus motu-Koita

description: 5. Sapindus motu-koita A.R. Franck, sp. nov. (LSID: 77340322-1) (Figures 1 and 10).
Type:— PAPUA NEW GUINEA. Central: Hill, Tana Highway, road to Brown R. Port Moresby subdistrict, 9° 30’ S, 147° 10’ E, 10 m, 7 August 1974, P. Katik s.n., LAE 62318 (holotype, LAE215500!; isotypes, A01771341!, BISH406609!, BRI-AQ0320796!, CNS-QRS 19773.1!, L2311311!, L2311313!, US01056781!).
Diagnosis:— Sapindus motu-koita has small mericarps (9–12 mm wide) like S. balicus and S. tricarpus. The distinctive characters of S. motu-koita are the petiolules 0–1 mm long, leaflet blades 1.5–2.5 times longer than wide with prominulous to obscure reticulate venation, and the pericarp 0.4–0.6 mm thick (vs. petiolules 1–4 mm long, leaflet blades 2.5–3.5 times longer than wide with strongly prominent reticulate venation, and pericarp 0.1 mm thick in S. balicus; and petiolules 0–1 mm long, leaflet blades 2.5–5.5 times longer than wide with prominulous to nearly obscure reticulate venation, and pericarp 0.1 mm thick in S. tricarpus).
Etymology:—For the Motu-Koita people, the indigenous inhabitants of the Port Moresby region of Papua New Guinea (Goddard 2020), where this species of Sapindus occurs.
Description:—Tree, to 15 m tall, bark smooth to rough, light to mottled gray with green fleck. Petiole 2–4 cm long, glabrous to sparsely puberulent; rachis glabrous, unwinged or wings to 5 mm wide on one side; leaflets 4–8; petiolule 0–1 mm long, pubescent; leaflet blade broadly ovate to ovate-lanceolate, generally symmetric, generally straight, the apex obtuse to shortly acuminate-obtuse, 4.5–12 cm long, 2.1–4.9 cm wide, 1.5–2.5 times longer than wide, adaxially drying pale green, glabrous, midrib pale green to pale yellow, at mid-blade the ridge 0.3 mm wide, 0.2 mm high, the blade even with the midrib or slightly ascending towards it, secondary veins pale green to pale yellow, tertiary and quaternary venation prominulous to obscure, intermediate in color between the secondary veins and blade surface to nearly concolorous with the blade surface, abaxially drying pale green, glabrous, midrib pale green to pale yellowish green, secondary veins pale green, prominulous, tertiary and quaternary venation prominulous to obscure, intermediate in color between the secondary veins and blade surface to nearly concolorous with the blade surface; exudates clear, inconspicuous abaxially on the blade surface. Petal without appendages. Mature mericarp 9–12 mm wide, pericarp 0.4–0.6 mm wide, seed 6–9 mm wide.
Distribution, habitat, and phenology:— Papua New Guinea (Fig. 4), 0– 80 m. Eucalyptus forest, mangrove swamp, monsoon scrub. Flowering March–May.
Notes:—This species is distinguished by its leaflet blades 1.5–2.5 times longer than wide with relatively obscure venation nearly concolorous with the blade surface, mature mericarps 9–12 mm wide, pericarp 0.4–0.6 mm wide, and seeds 6–9 mm wide. It is endemic to Papua New Guinea. Previously specimens had been identified as S. saponaria (Leenhouts 1994). In addition to its distinctive morphology, the species is about 3,000 –4,000 km away from the nearest native populations of other species of Sapindus (i.e. S. balicus, S. tricarpus, and S. vitiensis).
Conservation Status:—The species is known from a few subpopulations in a relatively small extent of occurrence (<5,000 km 2). Given the likelihood for continuing decline due to deforestation or forest degradation, the species ought to be deemed Endangered (IUCN 2012).
Specimens examined:— PAPUA NEW GUINEA. Central: 1 mi. SE of Kapa Kapa, 50 ft., 14 August 1962, Schodde 2779 (BO, US); Fairfax Harbour, 9° 55’ S, 147° 20’ E, sea level, 16 February 1965, Gillison NGF 22222 (A, BISH, PNH, US); Rigo Road 13 mile, Moresby subdistrict, 25 June 1969, Streimann NGF 39489 (A); near Mt. Lawes, Moresby subdistrict, 9° 10’ S, 147° 15’ E, 250 ft., 24 March 1971, Womersley NGF 43704 (BISH, GH, PNH).
description: Published as part of Franck, Alan R., 2024, Revision of Sapindus sect. Sapindus (Sapindeae, Sapindoideae, Sapindaceae), including the description of three new species, pp. 1-71 in Phytotaxa 648 (1) on pages 28-30, DOI: 10.11646/phytotaxa.648.1.1, http://zenodo.org/record/13215835