Sapindus tricarpus (Blanco) A.R. Franck

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 : 52-53

11. Sapindus tricarpus (Blanco) A.R. Franck , comb. nov. (LSID: 77340326-1) ( Figure 17 ).

≡ Quassia tricarpa Blanco (1837: 351) .

≡ Sapindus turczaninowii Vidal y Soler (1883a : xxi, lám. 34A(1-7)), nom. illeg.

Neotype (first-step designated by Leenhouts 1994, second-step designated here):— Philippines. Luzon , Rizal Prov., Antipolo. E. D. Merrill: Species Blancoanae no. 183 ( L0014583 !; isoneotype, A00249537 !).

= Sapindus saponaria forma microcarpus Radlkofer (1900: 517) .

Neotype (designated here):— Philippines. Luzon , Rizal Prov., Antipolo. E. D. Merrill: Species Blancoanae no. 183 ( L0014583 !; isoneotype, A00249537 !, BO?).

Etymology:—In reference to the 3-carpellate ovary and fruit.

Description:—Tree, to 20 m tall, bark not observed. Petiole 1.8–5.1 cm long, glabrous; rachis glabrous, unwinged or wings on one side to 5 mm wide; leaflets 6–10(12); petiolule 0–1 mm long, glabrous; leaflet blade lanceolate to narrowly lanceolate, rarely ovate, asymmetric to nearly symmetric, falcate to nearly straight, the apex acuminate with an acute to obtuse tip, 5–19 cm long, 2.3–5 cm wide, 2.5–5.5 times longer than wide, adaxially drying green to brownish green, glabrous, midrib pale yellow to brownish yellow, at mid-blade the ridge 0.2–0.4 mm tall, 0.1–0.2 mm wide, blade not or only scarcely sunken along the midrib, secondary venation pale yellowish, tertiary venation prominent to prominulous, quaternary venation prominulous to nearly obscure, nearly concolorous with the blade surface, abaxially drying pale green to pale brownish green, glabrous, secondary venation pale yellow, tertiary venation prominulous, discolorous to nearly concolorous with the blade surface, quaternary venation prominulous to obscure; foveolae conspicuous on the abaxial leaflet blade surface, exudate clear. Petal without appendages. Mature mericarp 9–12 mm wide, pericarp 0.1 mm wide, seed 7–10 mm wide.

Distribution, habitat, and phenology:— Bulacan, Ilocos Norte, Laguna, and Rizal provinces of Luzon, Philippines ( Fig. 4 ); 50– 500 m. Lowland mixed forest ridge slopes, open forest, and upland forest. Flowering September–November.

Notes:— Sapindus tricarpus is characterized by its subsessile leaflets with somewhat obscure venation, petals lacking appendages, and small fruits. The name is a new combination from the basionym Quassia tricarpa ( Blanco 1837, 1845). Merrill (1918) indicated that Blanco’s description of Q. tricarpa “undoubtedly” was referring to a species of Sapindus , but also that it was “probably” partly based on Guioa koelreuteria (Blanco 1838: 289) Merrill (1918: 241) . Somewhat consistent with this, Blanco (1878: 94 & t. 388) had later listed Sapindus forsythii (= S. saponaria ) as a synonym of Q. tricarpa . Since no original material is known to be extant for Blanco’s names, Merrill assembled and distributed a set of specimens “that to a large degree would take the place of Blanco’s ‘types’ which were never preserved”; these have often been chosen as neotypes for Blanco’s names ( Nicolson & Arculus 2001). For Q. tricarpa, Leenhouts (1994) identified the gathering and listed BO and L but did not specify either as the foremost neotype. The specimen at L is selected as neotype since a specimen at the BO herbarium could not be located (R. Damayanti, pers. comm.).

According to Merrill (1918), Blanco’s (1837) Sapindus saponaria was misapplied to Guioa pleuopteris ( Blume 1847: 158) Radlkofer (1879: 10) , although Radlkofer (1878) thought he might be referring to a species of Erioglossum Blume (1823: 229) (= Lepisanthes Blume [1825: 237] ). Sapindus turczaninowii (see also Vidal y Soler 1883b: 98, 1885) is illegitimate, citing the earlier legitimate name Quassia tricarpa .

In the protologue of Sapindus saponaria forma microcarpus, Radlkofer (1900) did not attribute any specimens to this form, but cited S. turczaninowoii and Sapindus microcarpus sensu Jardin (1857 , 1858) in synonymy. Radlkofer’s forma microcarpus is taken to be synonymous with S. turczaninowoii but Jardin’s S. microcarpus refers to a different species ( S. saponaria subsp. jardinianus ) from the Marquesas with larger fruits. Like S. balicus and S. motu-koita, Leenhouts (1994) described S. tricarpus as “distinguishable” and “rather uniform” but treated it as a synonym and race of S. saponaria .

According to some specimens (Anonymous s.n., Mulato s.n., Sulit 845, Sulit s.n., and Valdez s.n.), the species is resistant to strong wind, flowers are showy, fruits are creamy and pale yellow to whitish when ripe and attract different species of birds, the fiber is used for cordage, and the bark is useful as a soap or fish poison.

Conservation Status:—The species is known only from the island of Luzon, including three provinces around Manila as well as one province on the north side of the island. Considering the total land area of these four provinces as the extent of occurrence (<10,000 km 2), the few known locations for the species, and the significant deforestation on Luzon, S. tricarpus should be categorized as Vulnerable ( IUCN 2012).

Specimens examined:— PHILIPPINES. Throughout the Philippines , [without date, without collector] Anonymous s.n. ( PNH) . Luzon : Rizal Province, Antipolo, February 1904, Ahern’s collector 25 ( A, MICH, US) ; Rizal Province, San Mateo , September 1904, Ahern’s collector 166 ( PNH) ; Laguna Province, Mt. Maquiling , 23 October 1907, Curran & Merritt 7707 ( BO) ; Laguna Province, Mt. Maquiling , September 1912, Forestry Bureau no. 19813, Whitford 2-26 ( LY) ; Bulacan Province, Angat , September 1913, Ramos s.n. ( A) ; Ilocos Norte Province, Bangui, November 1923, Bureau of Science no. 43525, McGregor 2-107 ( A) ; Laguna Province, Mt. Makiling , 11 October 1937, Brown 3765 ( A) ; Makiling National Park , 120 m, 10 October 1945, Sulit 845 ( PNH) ; Laguna Province, Mt. Makiling , 120 m, 30 January 1955, Sulit s.n. ( PNH) ; ibid., 110 m, January 1955, Agra s.n. ( PNH) ; ibid., 8 February 1955, Valdez s.n. ( PNH) ; ibid., 110 m, 22 March 1955, Mulato s.n. ( PNH) ; Manila, Sep-October 1958, Vidal 218 ( MA) ; ibid., Vidal 1225 ( MA) ; Ilocos Norte Province, Mt. Napidad, Brgy. San Isidro, Bangui , 14° 12.9’ N, 120° 38.3’ E, 500 m, 17 February 1997, PPI No. 25264, Garcia & Fernando s.n. ( BRIT) .

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 17. Sapindus tricarpus, clockwise from top-left: fertile branch (Ahern’s collector 25, courtesy of the United States National Herbarium [US], Smithsonian Institution), flower adaxial side (McGregor 2-107, A), leaflet adaxial surface (Garcia & Fernando s.n., BRIT), leaflet abaxial surface (Garcia & Fernando s.n., BRIT), and petiole base (Ramos s.n., US).