2. Philadelphus texensis S. Y. Hu, J. Arnold Arbor. 37: 54. 1956.
Shrubs, 6–15 dm. Stems spreading, green to yellowish, weathering grayish and striate, divaricately branched, moderately to sparsely strigose-sericeous; internodes 1.5–5.5 cm (long shoots), 0.2–2.2 cm (lateral branches); axillary buds exposed. Leaves: petiole 2–4.5(–8) mm; blade grayish or whitish abaxially, green adaxially, usually narrowly lanceolate to lance-ovate, sometimes ovate, (1–)1.6–3.3(–4.7) × (0.4–)0.5–1.1(–2.3) cm, ± herbaceous, margins usually entire, rarely sparsely serrulate, plane, sometimes drying revolute, abaxial surface densely and loosely strigose, hairs arched-twisted, 0.3–1.2 mm, with or without understory of coiled-crisped, slender hairs between raised veins, adaxial surface sparsely to moderately strigose, hairs antrorsely appressed, 0.4–0.9 mm, 1–3 hairs per mm of width. Inflorescences: flowers solitary. Pedicels 1–2(–4) mm, loosely strigose or glabrous. Flowers: hypanthium loosely strigose or glabrous; sepals ovate to ovate-lanceolate, 2.5–5.5 × 1–2.5 mm, apex obtuse to long acuminate-caudate, abaxial surface loosely strigose or glabrous, adaxial surface glabrous except ciliate and villous along distal margins; petals white, oblong-ovate to ovate, 8–10(–14) × 3.5–5(–10.5) mm, margins entire to undulate, apex obtuse to notched; stamens (11–)14–16(–24); filaments distinct, 1–4.7 mm; style 1, clavate, 1.9–3(–3.5) mm, slender base 0.5–2 mm; stigmatic portion obovoid, 1.2–1.7 × 1.1 mm. Capsules turbinate-spheroid, 3.5–5.5 × 3.5–5 mm, sepals at distal 1/3, tardily falling, capsule distal surface smooth or impressed in 4 vertical lines. Seeds short-caudate distally, 1–1.2 mm.
Varieties 2 (2 in the flora): Texas, n Mexico.
A. E. Weakley (2002) found that the ITS sequences of Philadelphus texensis and P. mearnsii do not differ, suggesting that they are very closely related.