Ayenia limitaris
Ayenia pilosa
kidney petal, Rio Grande ayenia, Tamaulipan kidney petal, Texas or Rio Grande ayenia
dwarf ayenia, hairy ayenia
petiole to 2.5(–4) cm;
blade ovate to ovate-lanceolate, unlobed, (3–)5–12.5 × (1.7–)3.2–7.5 cm, noticeably reduced in size distally on stem, base rounded to cordate, margins irregularly dentate to dentate-crenate, apex acute to acuminate, 7-veined from base, surfaces: abaxial tomentulose, adaxial sparingly stellate-pubescent.
petiole 0.5–1 cm;
blades of proximal leaves broadly ovate to orbiculate, 0.5–1.3 × 0.5–1.1 cm, distal ovate to oblong-ovate or oblong-lanceolate, unlobed, 0.5–2(–3.5) × 0.4–1.4(–1.7) cm, base cordate, margins serrate to doubly serrate, ciliate with 1+ bristles per tooth, apex acute, 3–5-veined from base, surfaces moderately to sparingly hirsute, hairs usually simple, bifurcate, and fasciculate, sometimes also stellate.
3–7 mm.
1.5–2 mm.
sepals caducous, not persistent in fruit, reflexed at anthesis, ovate-lanceolate, 3 mm, stellate-pubescent abaxially;
petal claws 2.5 mm, lamina reniform, 1 × 1.5 mm, base deeply lobed, lobes ovate-rounded, margins ± entire, apex entire, surfaces glabrous, abaxial appendage absent;
androgynophore 0.2–0.3 mm;
stamen filaments absent or nearly so;
stigmas slightly exserted.
sepals persistent, not reflexed at anthesis, ovate, 2 mm, sparingly stellate-hairy abaxially;
petal claws 4 mm, lamina rhombic, 1 × 1 mm, base attenuate on claw, margins entire, apex notched, surfaces sparingly hairy abaxially, hairs simple, multicellular, abaxial appendage cylindric to slightly clavate, 0.5 mm;
androgynophore 1.5 mm;
stamen filaments present;
stigmas slightly exserted.
oblate, 6–7 × 8–10 mm, densely short stellate-pubescent, prickles 1–1.5 mm.
subspheric, 3–3.5 × 3.5 mm, sparingly stellate-hairy, prickles 0.5 mm.
3–5 mm, tuberculate.
2–2.5 mm, sparingly tuberculate.
axillary, not borne on short shoots (brachyblasts), 2 or 3(or 4)-flowered;
peduncle to 10 mm.
axillary, not borne on short shoots (brachyblasts), (1 or)2 or 3-flowered;
peduncle 2–3 mm.
Ayenia limitaris
Ayenia pilosa
Of conservation concern.
Ayenia limitaris was designated an endangered species by the U.S. Fish and Wildlife Service in 1994. In the flora area, the species is known only from near the mouth of the Rio Grande.
Ayenia limitaris is in the Center for Plant Conservation’s National Collection of Endangered Plants.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Leaf shape and vestiture are the principal characters used to distinguish Ayenia pilosa from A. filiformis. Where they co-occur in southwestern Texas there are intermediates in which the leaves are oblong-ovate as in A. pilosa but the vestiture is more like that of A. filiformis.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
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USDA Plants Database
