Vauquelinia californica

(Torrey) Sargent

Gard. & Forest 2: 400. 1889.

Common names: Arizona rosewood
Illustrated
Basionym: Spiraea californica Torrey in W. H. Emory, Not. Milit. Reconn., 140. 1848
Treatment appears in FNA Volume 9. Treatment on page 430.

Shrubs or trees, rounded to ovoid, 10–50(–80) dm, usually multistemmed. Leaves: petiole (1.5–)4–16(–26) mm; blade usually bicolor, sometimes green or yellow-green, oblong-elliptic or oblong-lanceolate to linear-lanceolate or linear, (2.2–)3–11(–15) × (0.6–)0.7–2(–3.2) cm, base obliquely cuneate to rounded, margins serrulate or crenulate, teeth 10–35(–50) per 5 cm, 0.1–0.5(–1.5) mm, apex acute, mostly mucronate, surfaces closely villous-tomentulose, abaxially more densely so, or glabrate or tardily glabrescent (some remaining crinkled hairs). Corymbs 1.5–5(–12) × 1.7–8(–13) cm, tomentulose, sometimes sparsely hairy or glabrate. Flowers: hypanthium 1.5–2.5(–3) × 2–3.7(–4.5) mm, tomentose to sparsely tomentulose or glabrate; sepals 1.1–2.2 × 1.4–2.3 mm, margins eglandular; petals oblong-ovate, 3.4–5.4 × 2.4–3.5 mm; filaments 2.5–6 mm. Capsules 4.5–6.5 × 3.5–4.5 mm. Seeds 3.5–5 × 0.9–1.4 mm.

Discussion

Subspecies 4 (3 in the flora).

Subspecies retherfordii (I. M. Johnston) W. J. Hess & Henrickson is known from Coahuila and Durango in northern Mexico.

Key

1 Leaves green or yellow-green, glabrate or puberulent along midveins. Vauquelinia californica subsp. pauciflora
1 Leaves bicolor, abaxially white-puberulent or villous-tomentulose (or tardily glabrescent in plants of c Arizona), adaxially green > 2
2 Leaf blades lanceolate to oblong-lanceolate or narrowly elliptic, (0.7–)1–2(–3.2) cm wide, usually abaxially sparsely white-puberulent, sometimes glabrate or glabrous. Vauquelinia californica subsp. californica
2 Leaf blades linear to linear-lanceolate, (0.6–)0.7–1.2(–1.4) cm wide, abaxially villous-tomentulose, soon or tardily glabrescent except for hairy midveins. Vauquelinia californica subsp. sonorensis