Sapindus saponaria subsp. jardinianus

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 : 44-46

8b. Sapindus saponaria L. subsp. jardinianus Brown ex A.R. Franck , subsp. nov. (LSID: 77340324-1) ( Figures 1 and 14 ).

≡ Sapindus saponaria L. var. jardiniana Brown (1935: 160) , nom. inval..

Type:— FRENCH POLYNESIA. Marquesas: Nukuhiva, Taiohae , alt. 200 m, 27 March 1922, F. B. H. Brown 1113 (holotype:

BISH 1004962!).

Diagnosis:— Sapindus saponaria subsp. jardinianus is similar to S. saponaria subsp. saponaria . The distinctive characters of subsp. jardinianus are the leaflet blades broadly ovate, elliptic, to lanceolate, 1.6–2.7(3.5) times longer than wide, on mature stems (5) 7–19 cm long, (2.7) 4.5–7.6 cm wide, usually symmetric or nearly so, not or only slightly falcate, glabrous, adaxially drying green to pale green (vs. leaflet blades lanceolate, ovate, elliptic, to obovate, 1.8–3.5[4.5] times longer than wide, on mature stems 3–12[14] cm long, 1.5–5 cm wide [to 32 cm long and 7.5 cm wide on immature stems], symmetric to asymmetric, straight to falcate, glabrous to pubescent, adaxially drying pale green, green, to pale brownish green in subsp. saponaria ).

Etymology:—Named for Désiré Édélestan Stanislas Aimé Jardin, of the French Navy, who studied the biota of French Polynesia in the 1850s ( Jardin 1857, 1858), the Latin termination following Art. 60.8d (Turland et la. 2018).

Description:—Tree, to 15 m tall, bark smooth and lightly roughened. Petiole 2–4(9) cm long, glabrous to sparsely puberulent, pale yellow to pale orange-yellow; rachis glabrous to sparsely puberulent, unwinged or frequently winged, the wings to 6 mm wide on one side, glabrous; leaflets (4)6–10(12); petiolule 0–2 mm long, glabrous to sparsely puberulent; leaflet blade broadly ovate, elliptic to lanceolate, symmetric or nearly so, straight to slightly falcate, the apex acuminate, to obtuse, 5.5–19 cm long, 2.7–7.6 cm wide, 1.6–2.7(3.5) times longer than wide, adaxially drying green to pale green, glabrous to very sparsely strigose, midrib ridge pale green to pale yellow, at mid-blade the ridge 0.1–0.3 mm wide, 0.2–0.3 mm high, the blade even with the midrib base or slightly sunken along the midrib, secondary veins pale yellow to pale greenish yellow, tertiary venation prominulous, quaternary venation prominulous to nearly obscure, slightly pale and discolorous with the blade surface, abaxially drying green to pale green, secondary veins pale green to pale yellow, tertiary venation prominulous to nearly obscure, nearly concolorous with the blade surface; foveolae conspicuous on the abaxial leaflet blade surface, exudate clear. Petal without appendages. Mature mericarp subglobose, 14–20 mm wide, pericarp 0.2–2 mm wide, seed 11–14 mm wide.

Distribution, habitat, and phenology:— Cook Islands, French Polynesia, and Hawaii ( Figs. 2 & 3 ). Dry to mesophytic lowland forests, gulches, and cliffs; 0- 600 m. Flowering January–December.

Notes:—The plants of S. saponaria subsp. jardinianus are fairly morphologically uniform, with the leaf rachis often winged and the leaflets usually broadly elliptic to broadly ovate and glabrous to glabrate. This subspecies is separated by over 4,000 km from the nearest populations of S. saponaria subsp. saponaria (on Clarion Island, Mexico). Some specimens of S. saponaria subsp. jardinianus appear starkly distinct with very large, glabrate elliptic leaflets subtending the inflorescence (e.g. Decker 1059 and Flynn & Lorence 5882). However, other specimens of S. saponaria subsp. jardinianus (e.g. Gillett 2211 and Perlman & Wood 19045) seem scarcely distinguishable from some specimens of S. saponaria subsp. saponaria from Ecuador or Peru (e.g. Bonifaz 1070, Cook & Gilbert 1059, Suclli & Farfán 1199). Because of their morphological uniformity, disjunct distribution, and subtle morphological differentiation, the plants of the Cook Islands, French Polynesia, and Hawaii are recognized as a subspecies, but perhaps further studies may change their taxonomy.

Plants of S. saponaria subsp. jardinianus can be deciduous during the dry season ( Papy 1954). The taxon occurs in four main areas which are all disjunct from each other by about 700–1,500 km: the Cook Islands, Society archipelago ( French Polynesia), Gambier archipelago ( French Polynesia), and the Marquesas archipelago ( French Polynesia). It is said to be common in the Marquesas, but rare in the Society archipelago ( Papy 1954).

Brown (1935) attempted to erect the variety S. saponaria var. jardiniana , nom. inval., in reference to Jardin (1857, 1858) who had discussed uses of the plant in the Marquesas. Jardin gave no description and did not introduce a new name. With uncertainty, Jardin (1857, 1858) had misapplied the name S. microcarpus Ruiz & Pavon (1957: 165 , pl. 341), this name being described from South America, which is evidently a species of Allophylus Linnaeus (1753: 348) ( Radlkofer 1878), and an illegitimate later homonym of S. microcarpus Wight & Walker-Arnott (1834: 112) (a species of Meliosma Blume [1823: 10] fide Beddome 1863). At the beginning of 1935, Latin diagnoses were required for valid publication ( Turland et al. 2018: Art. 39.1) and, unfortunately, Brown (1935) did not include a Latin diagnosis. Thus, Brown’s (1935) name was invalid. The epithet is here validly published as a subspecies, ironically, without a Latin diagnosis, since beginning in 2012, English also suffices ( Turland et al. 2018: Art. 39.2).

Brown (1935) considered his variety to be endemic to the Marquesas, having “relatively larger, commonly elliptical leaflets” compared to similar specimens from the Society Islands having the leaflets “commonly ovateelliptical.” Here these are both considered part of the same taxon, S. saponaria subsp. jardinianus .

A very surprising occurrence is documented by a specimen of S. saponaria subsp. jardinianus collected from Hawaii in the 1850s (Remy 566). Though having seen this specimen, neither Rock (1913) nor Skottsberg (1926) noticed it differed from the Hawaiian endemic S. thurstonii . The historic occurrence of S. saponaria subsp. jardinianus in Hawaii is here presumed a native occurrence, but it is doubtful the population is extant in Hawaii. The nearest extant population of S. saponaria subsp. jardinianus is from Eiao in the Marquesas, French Polynesia (ca. 3,500 km away from Hawaii).

Plants of S. saponaria subsp. jardinianus are treated as native to the Pacific Islands, possibly the result of an ancient dispersal from South America. Some studies have highlighted French Polynesia as the most likely set of Pacific islands to receive drift from South America ( Ioannidis et al. 2020, Temmen et al. 2022). However, an ancient human introduction to the Pacific Islands is worth considering during the supposed admixture event that occurred ca. AD 1200 that may have introduced sweet potato to the Marquesas from Colombia ( Ioannidis et al. 2020).

Archaeological charcoal samples indicate Sapindus wood was frequently utilized for fuel by early indigenous peoples in the Marquesas ( Huebert & Allen 2016). The wood is said to be valued in the Cook Islands ( Sykes 2016). Plants were prized for firewood and tool handles according to Decker 1233. The leaflets were eaten by caterpillars according to Gillett 2211, and the caterpillars hosted by S. saponaria subsp. jardinianus were an important food source for the Marquesan imperial pigeon ( Blanvillain & Thorsen 2003). A photo of a flowering tree is depicted by Mueller-Dombois & Fosberg (1998: photo 8F. 3) and Lorence & Wagner (2020: Fig. 373). A photo of a sterile plant was provided by Butaud (2013).

Conservation Status:—Extant subpopulations being confined to small islands, the total land area or extent of occurrence is quite small (<5,000 km 2). The islands are often rather distant, causing some fragmentation to the population, and continuing decline in the population is likely. Therefore, the subspecies ought to be classified as Endangered ( IUCN 2012).

Specimens examined:— COOK ISLANDS. Mauke: at Kimiangatau, 18 April 1985, Whistler 5519 (BISH). FRENCH POLYNESIA. “Friendly Islands” [Society Islands], 1769, Banks & Solander 526.1 (BM). Leeward Islands: Raiatea Island, above town of Opoa, 7 December 1926, Moore 406 ( US);Tahaa, Mt. Purauti, east ridge, 11 October 1934, St. John 17383 (A, US); Bora Bora, Nunue, Motu Toopua, Secteur Nord-Est, 151 46 W, 16 31 S, 130 m, 4 December 1993, Florence 12035 (PAP). Marquesas Islands: [1800s], “Kokuu”, Jardin s.n. (P); Noukouhiva [Nukuhiva], 1844, Le Batard s.n. ( US); Eiau [Eiao], 28 September 1922, Jones 1542F (BISH); Hiva’oa Island, road from Atuona to Tahauku, 5 October 1963, Sachet 1219 (PAP, US); Hiva’oa Island, above eastern Puamau Bay near Hanatevai, 17 October 1963, Decker 664 ( US); Hiva’oa Island, Eastern Puamau valley, 22 October 1963, Decker 732 ( US); Hiva’oa Island, Western Puamau Valley, 2 November 1963, Decker 840 ( US); Hiva’oa Island, Central Puamau Valley, 10 December 1963, Decker 1059 ( US); Hiva’oa Island, Natue Valley, 15 December 1963, Decker 1233 ( US); Hiva’oa Island, between Hanamenu & cave Anatuakina, 8 January 1964, Decker 1284 ( US); Hiva’oa Island, Hanamenu Valley, 9 January 1964, Decker 1306 ( US); Uahuka Island, east of main Vaipae’e canyon and north of Tahoatikikau crater, 21 February 1964, Decker 1592 ( US); Uahuka Island, east flank of Vaipae’e valley, 2 March 1964, Decker 1753 ( US); Nukuhiva Island, interfluve above Uea Valley, near Baie Marquisienne, 20 April 1964, Decker 2045 ( US); Nukuhiva Island, Taiohae- Hatiheu trail, 5 May 1964, Decker 2201 ( US); Nukuhiva Island, east flank of Taiohae Bay ca. 1 km S of hospital, 7 May 1964, Decker 2218 ( US); Uapou Island, Hakahetau Valley, 15 May 1964, Decker 2320 ( US); Tahuata Island, Puhiae, Ivaiva nui, 14 February 1968, Sinoto 10 ( US); Nukuhiva, Uea Bay, 7 km W of Taiohae, 27 July 1970, Gillett 2211 (GH, US); Motane Island, 5 March 1973, Hallé 2102 ( US); Tahuata Island, 18 March 1974, Hallé 2187 (MPU, US); Mohotani Island, central part of island, 16 November 1974, Decker 2802 ( US); Tahuata Island, Vaitahu, 31 January 1975, Schafer 5151 ( US); Mohotani Island, 18 March 1975, Schäfer 5336 ( US); Nukuhiva Island, between Taihai Bay & Hooumi Bay, 20 July 1977, Gagné & Montgomery 1125 ( US); Nukuhiva Island, SW side, Baie Marquisienne, 5 August 1977, Gagné 1279 ( US); Nukuhiva, 31 July 1985, Toutain 4270 (PAP); Eaio, Vallée d’Opituha, 170 m, 18 July 1987, Thibault 1013 (PAP); Eiao, 460 m, 25 July 1987, Thibault 1065 (PAP); Eiao, Opituha, 350 m, 27 July 1987, Thibault 1069 (PAP); Ua Pou, past Haakuti, 7 July 1997, Perlman et al. 15936 ( US); Ua Huka, Haahue valley, NW side of island, 19 June 2004, Perlman & Wood 19045 ( US). Tuamotu-Gambier Islands: Mangareva Island, Mt. Duff, south side, 30 May 1934, St. John 14729 (A). Windward Islands: Otaheiti, “1775” [see Nicolson & Fosberg 2004: 35], Cook s.n. (BM); Tahiti, Punaauia, Montée du Lotus, 22 March 2004, Butaud 409 (PAP); Tahiti, Maruapo, 1 August 2004, Butaud 555 (PAP); Tahiti, Rebord plateau Tamanu, 520 m, 10 May 2005, Butaud et al. 1086 (PAP); Tahiti, 2005, Teamotuaitau 32 (PAP); Tahiti, Vallée Atehi, Punaauia, 50 m, 15 September 2005, Teamotuaitau 57 (PAP). HAWAII. Iles Sandwich, 1851–1855, Remy 566 (P); Maui, Kahanu Garden, ex Nukuhiva, 16 November 1995, Flynn & Lorence 5882 [cultivated] (BISH).

Figures

FIGURE 1. Morphology of various species of Sapindus. A. Habit of S. thurstonii, from Rock (1913, Pl. 106). B. Mature fruit of S. motukoita (Schodde 2779, US). C. Mature fruit of S. saponaria subsp. jardinianus (Decker 2802, US). D. Immature fruit of S. trifoliatus (West s.n., FLAS). E. Immature fruit of S. rarak (Chow & Wan 80094, BISH). F. Adaxial side of petal of S. delavayi (Maire s.n., BISH). G. Adaxial side of petal with a sepal behind and an adjacent stamen of S. trifoliatus (Nageswara-Rao s.n., FLAS). H. Adaxial side of petal with the pistil along bottom of S. oahuensis (Degener 7356, US).

FIGURE 2. Morphology of various species of Sapindus. Top-left: seedlings of S. mukorossi (Franck 5932, FLAS), top-middle: seedling of S. saponaria subsp. saponaria (Wilder et al. 31737, SWF; photo by K. Relish), top-right: foliaceous cataphyll at base of newly emerging shoot of S. drummondii var. glabratus (Trelease 60, MO), bottom-left: exudates (e.g. white arrow) of glandular foveolae on abaxial leaflet surface of S. standleyi (Neill 2203, MO), and bottom-right: exudates (e.g. white arrow) of glandular foveolae on abaxial leaflet surface of S. mukorossi (Yonekura 96562, A).

FIGURE 3. Native distribution of cited specimens of Sapindus in the Americas and eastern Oceania (cultivated or naturalized occurrences are not mapped). Longer names of some taxa are abbreviated, i.e. S. drummondii var. drummondii (abbreviated as drum. var. drum.), S. drummondii var. glabratus (drum. var. glabratus), S. saponaria subsp. jardinianus (sap. subsp. jard.), and S. saponaria subsp. saponaria (sap. subsp. sap.), The symbol for the occurrence of S. saponaria subsp. jardinianus in Hawaii is placed beside Hawaii on the map.

FIGURE 14. Sapindus saponaria subsp. jardinianus, clockwise from top-left: fertile branch (Flynn & Lorence 5882, courtesy of the Bishop Museum [BISH]), petal adaxial surface (Hallé 2187, US), leaflet adaxial surface (Hallé 2187, US), leaflet abaxial surface (Decker 2802, US), and petiole base (Decker 2802, US).