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1 Rootstock with brown, gray, or dull red-brown cortex which does not exfoliate; stamens 7.
..2 Plant pubescent with spreading hairs 0.3-0.5 mm long (rarely glabrous); lower leaves elliptic, ovate, or obovate, usually prominently reticulate and firm in texture; upper leaves often narrower than the basal, but rarely lanceolate; [Edwards Plateau, s. TX, and adjacent s. TX and se. Coastal Plain]
..2 Plant pubescent with incurved hairs 0.07-0.15 (-0.2) mm long (rarely entirely glabrous, but the leaves frequently so); lower leaves linear to elliptic or ovate, thin to thick in texture, the upper leaves often markedly narrower than the lower leaves; [c. and n. TX]
1 Rootstock with bright orange-red cortex which exfoliates loosely in thin layers; stamens 8 or 7.
....3 Leaves of the lower stem elliptic to ovate, 1.5-3× as long as wide, the upper leaves similar or somewhat narrower (but never lanceolate or linear); stem pubescence mostly of loosely incurved hairs 0.15-0.3 mm long, the hair tips not close to the stem surface; [Goliad formation of s. TX]
....3 Leaves of the lower stem narrowly elliptic, lanceolate, or linear, > 5× as long as wide; stem pubescence of closely incurved-appressed hairs 0.07-0.15 (-0.2) mm long, with the free tip usually touching the stem; [se. TX Coastal Plain]