Philadelphus texensis var. texensis
Leaf blades (1–)1.6–3.3(–4.7) × (0.5–)0.6–1(–2.3) cm, abaxial surface loosely strigose, hairs 0.4–0.8 mm, with understory of white, more slender, tightly coiled-crisped hairs.
Phenology: Flowering Apr–May; fruiting Jun–Oct.
Habitat: Limestone slopes and ravines, slopes in oak-juniper woodlands.
Elevation: 200–400 m.
Distribution
Tex., Mexico (Coahuila).
Discussion
Variety texensis has a more westward range than var. ernestii; it is known from Bandera, Bexar, Edwards, Kendall, Medina, Real, and Uvalde counties in central Texas and is rare in the mountains of central Coahuila, Mexico. The two varieties are identical in all important characteristics, differing primarily in the presence or absence of the highly coiled-crisped of understory hairs on the abaxial leaf surfaces. There are several collections of var. texansis in which most leaves lack understory vestiture, as in var. ernestii, but the understory vestiture occurs on some leaves or branches indicating the expression or non-expression of a simple genetic trait. In both varieties, sepals can be glabrous or sparsely sericeous, even within a population.
Selected References
None.