Styrax platanifolius
Smithsonian Contr. Knowl. 6(4): 4. 1853 (as platinifolium),.
Shrubs, to 6 m, not suckering from roots. Leaves: petiole 6–20 mm; blade with 5–6 secondary veins, depressed-orbiculate or broadly ovate, 4.5–9(–12) × 4.2–9(–11.5) cm, margins entire, coarsely toothed, or 3-lobed, longest arms of abaxial hairs to 1 mm. False-terminal inflorescences 2–7-flowered or solitary flower, 2–5 cm; axillary flowers absent. Pedicels 4–9 mm, 1.3–2.3 times as long as calyx. Flowers: calyx 3–5(–6) × 4.5–5.5 mm; corolla 12–21 mm, tube 3–4 mm, lobes 5–6, imbricate in bud, slightly reflexed, elliptic, 11–18 × 3–7 mm; filaments connate 1–6 mm beyond adnation to corolla. Capsules globose, 7–10 × 7–11 mm (broader when 2–3-seeded), grayish white stellate-pubescent, dehiscent nearly or completely to proximal end, broadly exposing seed(s); fruit wall 0.3–0.5 mm thick.
Distribution
Tex., n Mexico (Coahuila, Nuevo León, Tamaulipas).
Discussion
Subspecies 5 (4 in the flora).
The treatment presented here is based on the morphological and molecular analyses of P. W. Fritsch (1996, 1997).
The only subspecies of Styrax platanifolius to occur outside the flora area is subsp. mollis P. W. Fritsch, from Nuevo León and Tamaulipas, Mexico. It grows in wooded canyons along the eastern escarpment of the Sierra Madre Oriental. All five subspecies are narrow endemics; of the four subspecies in the flora, three (subspp. platanifolius, stellatus, and texanus) occur only in the Edwards Plateau region of Texas; the fourth (subsp. youngiae) is known only from the Davis Mountains of western Texas and from northern Coahuila, Mexico.
Selected References
None.
Lower Taxa
Key
| 1 | Leaf blades with abaxial surface nearly glabrous or visible through pubescence | > 2 |
| 1 | Leaf blades with abaxial surface completely covered and obscured by pubescence | > 3 |
| 2 | Leaf blades glabrous except for scattered, orange-brown or dark-brown, stalked, stellate hairs abaxially on some; pedicels and calyces glabrous. | Styrax platanifolius subsp. platanifolius |
| 2 | Leaf blades with scattered, white, stellate pubescence in addition to scattered, orange-brown or dark-brown, stalked, stellate hairs abaxially on some; pedicels and calyces with white, stellate hairs. | Styrax platanifolius subsp. stellatus |
| 3 | Young twigs faintly glaucous; leaf blades glabrous adaxially; styles pubescent from proximal end to ca. 15-35% of total length; abaxial surface of leaf blades, pedicels, and calyces white stellate-tomentose. | Styrax platanifolius subsp. texanus |
| 3 | Young twigs stellate-pubescent; leaf blades stellate-pubescent adaxially; styles pubescent from proximal end to ca. 60-80% of total length; abaxial surface of leaf blades, pedicels, and calyces white stellate-lanate. | Styrax platanifolius subsp. youngiae |