Sapindus balicus Radlkofer (1878: 396)

Franck, Alan R., 2024, Revision of Sapindus sect. Sapindus (Sapindeae, Sapindoideae, Sapindaceae), including the description of three new species, Phytotaxa 648 (1), pp. 1-71 : 14-16

1. Sapindus balicus Radlkofer (1878: 396) ( Figure 5 ).

Type:— INDONESIA. Bali: Teysmann [ J. E. Teijsmann] s.n. (probable holotype, M-0224799!) .

Etymology:—In reference to Bali, Indonesia.

Description:—Tree, to 25 m tall, bark texture somewhat finely roughened, with few flaky chips or plates. Petiole 3–4.2 cm long, glabrous to pubescent, pale yellow and sometimes darker at the base, unwinged or wings to 4 mm wide on one side; rachis glabrous, unwinged or on leaves of immature stems with wings to 5 mm wide on one side; leaflets 6–8; petiolule 1–4 mm long, glabrous; leaflet blade ovate-lanceolate, lanceolate, oblong-elliptic, to oblanceolate, symmetric to lightly asymmetric, straight to lightly falcate, the apex obtuse, 5–9.5 cm long, 2–3.5 cm wide, 2.5–3.5 times longer than wide, adaxially drying green to pale yellow-brown, glabrous, midrib pale yellow, at mid-blade the ridge 0.1–0.2 mm wide, 0.1–0.3 mm high, the blade not sunken along the midrib, secondary veins pale green to pale yellow, often drying nearly concolorous with the blade, tertiary, quaternary, and quinternary venation strongly raised, prominent and conspicuous, or sometimes the quinternary venation prominulous and somewhat obscure, concolorous with the secondary veins and strongly discolorous to slightly discolorous with the blade surface, abaxially drying pale green to pale yellow-brown, glabrous to sparsely pubescent, midrib pale yellow-green to pale brown, secondary veins pale yellow, tertiary, quaternary, and quinternary venation raised, prominent and conspicuous, concolorous with the secondary veins and strongly discolorous with the blade surface; foveolae inconspicuous on the abaxial leaflet blade surface, exudate clear. Petal without appendages. Mature mericarp subglobose, 10–13 mm wide, pericarp 0.1 mm wide, seed 7–9 mm wide.

Distribution, habitat, and phenology:— Indonesia (South Sumatra to Lesser Sunda Islands) ( Fig. 4 ), 10– 500 m. Monsoon forest. Flowering March–June.

Notes:— Sapindus balicus is distinguished by its leaflet blades 2.5–3.5 times longer than wide with strongly prominent, raised reticulate veins, mature mericarps 10–13 mm wide, pericarp 0.1 mm thick, and seed 7–9 mm wide. Radlkofer (1878) was rather brief in describing S. balicus , placing emphasis on the papery, thin-skinned fruits and describing the leaves as having 2–3 pairs of elliptic to lanceolate-oblong leaflets. Although Leenhouts (1994) placed S. balicus in synonymy under S. saponaria , he categorized it (as well as S. motu-koita and S. tricarpus ) as a “race” that was “distinguishable” and “rather uniform.” It was listed in cultivation in Bogor, Indonesia ( Teijsmann & Binnendijk 1866, i.e. S. balicus as “Balie”). This species was accepted by Radlkofer (1932a, 1932b), consistent with the application here.

Conservation Status:—The species probably should be categorized as Least Concern ( IUCN 2012), owing to its large extent of occurrence based on the herbarium specimens cited below. However, a more critical examination of its subpopulations and the threat of local deforestation may change its classification.

Specimens examined:— INDONESIA. Java, Zollinger s.n. ( P) . East Nusa Tenggara: Soemba [Sumba Island], Pajeh, 15 March 1925, Iboet 3 ( BO) ; Soemba [Sumba Island], Lologooh, Laora , 12 April 1925, Iboet 255 ( BO) ; Kleine Soenda Eilanden, Soemba Waingapoe [Sumba Island, Waingapu], 6 June 1936, Voogd 2553 ( A) ; Kleine Soenda Eilanden Flores, West, Nangalili-Orong , 3 March 1968, Schmutz 2123 ( L) ; Nangalili, 29 March 1974, Schmutz 3628 ( L) ; Sumba, 14 July 1974, Verheijen 3933 ( BRIT, L) ; Sumba, 12 July 1974, Verheijen 4230 ( BRIT, L) . Lampung: Baie de Sanpoong-Sumatra, détroit de la Sonde, 1838–1840, Hombron s.n. ( P) . West Nusa Tenggara: W Sumbawa, Pernek, Olat Seli , ca. 12 km S of Sumbawa Besar , 19 May 1961, Kuswata 239 ( BO, L, P) .

Figures

FIGURE 4. Native distribution of cited specimens of Sapindus in eastern Asia and western Oceania (cultivated or naturalized occurrences are not mapped). Sapindus saponaria subsp. jardinianus is abbreviated as “sap. subsp. jard.”. The symbol for the occurrence of S. saponaria subsp. jardinianus in Hawaii is placed beside Hawaii on the map. Two species endemic to Vietnam (S. chyrsotrichus and S. sonlaensis) are not here considered to be part of sect. Sapindus.

FIGURE 5. Sapindus balicus, clockwise from top-left: fertile branch (Voogd 2553, courtesy of the Herbarium of the Arnold Arboretum of Harvard University, A), adaxial side of petal (Voogd 2553, A), leaflet adaxial surface (Verheijen 3933, BRIT), leaflet abaxial surface (Verheijen 3933, BRIT), and petiole base (Voogd 2553, A).