Shrubs or trees to 7.5 m, dioecious or monoecious. Bark grey or yellowish-grey, fissured, scaly. Branchlets greenish at first, pubescent, with shorter internodes relative to M. celtidifolia; lenticels pale, elliptic, dense and prominent. Winter buds elliptic to ovoid, 3–4 mm, apex acute; outer scales dark brown, pubescent and minutely ciliate. Stipules linear-lanceolate, 3–5 mm, papery, pubescent. Leaves lanceolate to ovate, occasionally lobed, 1–6 × (0.6–)1–4 cm, upper surface harshly scabrous, lower surface scabrous to pubescent; base rounded to nearly cordate; margins regularly serrate; apex acuminate to sub-caudate. Male inflorescences 1 per node, 0.5–1 cm, peduncle 0.2–0.8 cm; male flowers with green to reddish, rounded to ovoid calyx lobes, filaments filiform. Female inflorescences 0.8–1.2 × 0.5–0.7 cm, on a peduncle 0.3–0.7 cm, pubescent; female flowers with ovoid calyx lobes, ovary dark green, ovoid, 1.5–2 × 1 mm, glabrous, style absent, stigmas 2, papillate. Syncarps maturing red, purple, or black, short-cylindric, c. 1 cm. (Razdan & Dennis Thomas 2021; Wunderlin 1997).
Distribution Mexico Northern states United States Arizona, New Mexico, Oklahoma, Texas
Habitat In canyons on limestone and igneous slopes, usually along streams; 200–2200 m asl.
Taxonomic note Several works have adopted a broad interpretion of M. celtidifolia Kunth, sinking M. microphylla Buckley into it; several others treat them as separate species, including Flora of North America and Plants of the World Online (Plants of the World Online 2022) whose taxonomy is followed here.
Texas Mulberry is a species of the American southwest and adjacent regions of northernmost Mexico that barely earns itself a mention here; it is occasionally cultivated on the very fringes of our North American area, but no occurences in Europe have been traced in research for this account. The same is true of its southern cousin, Mexican Mulberry M. celtidifolia, and even where Texas Mulberry is grown it is almost always discussed under that name, as most authorities consider them synonymous and the name M. celtidifolia takes priority (see taxonomic note, above). Texas Mulberry is advocated for desert areas of the American southwest by Soule (2022) (discussed as M. celtidifolia). Native Americans, notably the Havasupai people harvested the fruit for food, but others consider the fruit to taste ‘insipid’ compared with introduced M. alba (Gibson 1913).