Sapindus drummondii Hooker & Arnott 1838
Creators: name: Franck, Alan R.
Publisher: name: Zenodo
Year: 2024
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Magnoliopsida
Sapindales
Sapindaceae
Sapindus
Sapindus drummondii

description: 2. Sapindus drummondii Hooker & Arnott (1838: 281).
≡ Sapindus saponaria var. drummondii (Hook. & Arn.) Benson (1943: 630).
≡ Sapindus saponaria subsp. drummondii (Hook. & Arn.) Murray (1983: 31).
Lectotype (lectotype, first-step designated by Benson 1943, second-step designated here):— USA. Texas: T. Drummond 54 (E00369036!; isolectotypes: G00096036!, G00096037!, GH00050886! [only the flowering specimen, fruiting specimen is Lindheimer 226], GH00050887!, GH00050888!, K000701893!, P02297183!).
= Rhus florita Jones (1933: 22).
Type:— USA. New Mexico: Florita, 7 September 1903, M. E. Jones s.n., Pomona herb. no. 86113 (holotype: RSA 0000628!).
Etymology:—Named for Thomas Drummond, a Scottish naturalist who collected plants (including the type specimens of S. drummondii) and birds in Texas in the early 1830s (Geiser 1937).
Description:—Tree, to 20 m tall. Petiole 2–7 cm long, glabrate, puberulent, to villosulous, light green, unwinged; rachis moderately pubescent to glabrate, unwinged or wing to 2.5 mm wide on one side of the rachis; leaflets 10–19; petiolule 0–7 mm long, glabrous to villous; leaflet blade narrowly lanceolate to lanceolate, strongly asymmetric to nearly symmetric, falcate to nearly straight, the apex acuminate with an acute to bluntly acute tip, 2–14 cm long, 0.6–3 cm wide, 2.5–17 times longer than wide, adaxially drying green, olive green, to brown-green, glabrous to sparsely puberulent, midrib pale yellow to pale green, at mid-blade the ridge ca. 0.1 mm wide, ca. 0.1 mm high, the blade even with the midrib base or scarcely sunken along the midrib, secondary veins pale green, tertiary venation prominulous to obscure, intermediate in color between blade surface and secondary veins, quaternary venation becoming obscure, abaxially drying pale green, glabrate to moderately pubescent, along the midrib proximally densely villous to villous-pubescent, midrib pale yellow, secondary veins prominent, pale green, tertiary venation prominulous, nearly concolorous with the blade surface, quaternary venation obscure; foveolae inconspicuous to conspicuous on the abaxial leaflet blade surface, exudates clear. Petal with 2 appendages, the appendage 0.1–0.6 mm long, sometimes apparently absent. Mature mericarp subglobose, glabrous, 8–16 mm wide, pericarp 0.25–2 mm wide, seed 6–10 mm wide.
Distribution, habitat, and phenology:— USA (Louisiana west to Arizona, north to Colorado, Kansas, and Missouri) and Mexico (Chihuahua, Coahuila, Nuevo Leon, Sonora, Tamaulipas, and Veracruz) (Fig. 3), 10–1500 m. Arroyos, bajada, bosque encino, bottomland forest, canyon bottom, deciduous forest, desert scrub, limestone glade, matorral, mesquite bosque, and riparian woodland. Flowering April–July (rarely February in cultivation).
Notes:— Sapindus drummondii is distinctive for its smaller fruits (Harrar & Harrar 1946, Duncan & Duncan 2000), petals usually with appendages (illustrated in Calónico-Soto 2011), foliaceous cataphylls, winter-deciduous leaves, and usually smaller and more numerous leaflets. Leaflets of S. drummondii can vary in size, with the narrowest leaflet blades occurring in the westernmost part of its range (esp. western Texas and Coahuila west to Arizona and Sonora).
Sometimes, S. drummondii has been considered an infraspecific taxon of S. saponaria (Benson 1943, Murray 1983, McNair & Andresen 2020), a synonym of S. saponaria (Standley 1923), or said to integrade with it (LaMotte 1935), but intermediate specimens were never explicitly identified.The flowering period of S. drummondii (April–July) is completely separate or nearly so from S. saponaria (September–March, rarely August, April, or July in the northern hemisphere), and the two appear to be allopatric or nearly so (Fig. 3; Felger et al. 2001). The species S. drummondii was accepted by Radklofer (1932a).
Sapindus drummondii shares similarities with S. marginatus (Brizicky 1963) and S. mukorossi, in that they have similar flowering periods, appendages on the petals, foliaceous cataphylls, and both are winter-deciduous. Sargent (1891) and Torrey & Gray (1840: 685) considered S. drummondii a synonym of S. marginatus; consequently, the name S. marginatus was often misapplied to S. drummondii (Torrey & Gray 1838: 255, Gray 1852, Emory 1859, Nuttall 1865: 19, Coulter 1891, Mohr 1901, Sudworth 1927). There are sufficient differences to keep them as separate species, and no intermediate specimens are known.
Torrey & Gray (1840: 685) and Benson (1943) both restricted S. drummondii to the unnamed α variety described by Hooker & Arnott (1838), excluding the ss variety (= S. saponaria) that they had also described. In agreement, Benson (1943) designated the type collection of S. drummondii, but no herbarium was selected. The specimen at E is selected as the lectotype, which bears the handwriting of Arnott (Noltie 2010). No Drummond specimen was located from Hooker’s herbarium, rather the Drummond specimen at Kew is from the Bentham herbarium.
Key to varieties of S. drummondii
1. Leaves densely villous to villous-pubescent abaxially along the petiolule and midrib basally .............................. var. drummondii
- Leaves glabrous, glabrate, to sparsely puberulent abaxially along the petiolule and midrib basally .......................... var. glabratus
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 16-17, DOI: 10.11646/phytotaxa.648.1.1, http://zenodo.org/record/13215835