Amorimia amazonica (Nied.) W. R. Anderson—Amazonian Peru and Bolivia and adjacent Brazil (Amazonas and Acre). Stems mostly sericeous to glabrate, occasionally velutinous to glabrate; lamina cuneate at base, originally loosely sericeous on both sides but soon glabrate or the abaxial midrib sparsely sericeous with straight appressed hairs, occasionally eglandular but usually bearing several tiny glands in abaxial surface parallel to margin but set in from it or very near margin at base; petiole 3–10 mm long, eglandular or biglandular near apex; stipules tiny, often caducous; inflorescence elongated, many-flowered, open, the axis tomentose or velutinous; bracts narrowly to broadly lanceolate, biglandular; bracteoles similar to bracts but smaller and sometimes eglandular; pedicel 4–10 mm long, often somewhat inflated at apex; sepals revolute in anthesis; petals small to medium-sized (limb of lateral petals 4–7 mm long), abaxially densely velutinous or tomentose over whole surface, adaxially glabrous or rarely velutinous only on claw; anthers glabrous; styles truncate or obtuse to apiculare dorsally at apex; samara velutinous or sericeous on nut and wings, the wings glabrate at maturity; lateral wings distinct at base and apex, the margin sinuate or coarsely dentate; dorsal wing tapered from nothing or a mere rib at base to a well-developed keel at apex, projecting between lateral wings, distinct at base and apex; ventral areole ovate or elliptical.
Amorimia concinna (C. V. Morton) W. R. Anderson—Cesar and Sucre [Bolívar and Magdalena], Colombia. Stems and inflorescence axis tomentose or velutinous to glabrate in age; lamina cuneate or rounded at base, originally densely velutinous on both sides, soon or eventually glabrate or the vesture persistent below, usually bearing 2 tiny marginal glands at very base and sometimes an additional pair of glands on margin somewhat above base; petiole (6–) 8–13 mm long, eglandular or biglandular near apex; stipules ca 1 mm long, linear, black, often deciduous; bracts and bracteoles linear, eglandular; pedicel 6–9 mm long; sepals revolute in anthesis; petals medium-sized (limb of lateral petals 6–8 mm long), abaxially sparsely sericeous in center of limb and otherwise glabrous, adaxially glabrous; anthers glabrous; styles dorsally acute or obtuse at apex, the stigma narrow and elongated; samara velutinous on nut and wings; lateral wings distinct at base and apex, the margin sinuate; dorsal wing 3–5 mm wide, widest toward apex but well-developed from base to apex, distinct at base and apex; ventral areole ovate. This species is rather different from the others in the genus, having the leaf glands marginal, both bracts and bracteoles linear and eglandular, and the petals only sparsely sericeous, but in other characters it fits here. In particular, the interpetiolar stipules, long spreading bracts and bracteoles, and butterfly-shaped samaras argue for its placement in Amorimia.
Amorimia exotropica (Griseb.) W. R. Anderson—Paraná, Santa Catarina, and Rio Grande do Sul, Brazil; Misiones, Argentina. Leaves mostly opposite, sometimes subopposite; lamina of larger leaves 6.5–13 (–19) cm long, 3–6.5 (–11) cm wide, often bearing 2 (–4) glands well above base and sometimes also biglandular at or just above base; petiole 5–12 (–20) mm long, eglandular or (rarely) biglandular on distal half; bracts raised on a slender petiole 0.5–1.5 mm long, often 1 mm; sepals recurved or revolute at apex in anthesis; styles dorsally acute or apiculate at apex; samara 1–3.3 cm high, 1.6–4 (–4.8) cm wide; lateral wings distinct at base and apex or connate at base, then often divided halfway to nut; ventral areole broadly ovate to rotund, 1–1.8 times as long as wide; otherwise resembling A. rigida, q.v. This species is quite variable, and at the same time not very different from the more northern populations treated in 2006 as A. rigida. The whole A. rigida complex deserves thorough study, especially the southern populations grouped here under the name A. exotropica.
Amorimia maritima (Adr. Juss.) W. R. Anderson.—Bahia and Espírito Santo, Brazil. Leaves often alternate or subopposite, sometimes opposite; lamina of larger leaves (8.5–) 10–15 cm long, 4.5–8 cm wide, usually biglandular at or just above base and eglandular distally; petiole 10–15 mm long, eglandular or biglandular near apex; sepals recurved or revolute at apex in anthesis; styles dorsally acute or apiculate at apex; samara 4.3–6 cm high, 5–8 cm wide; lateral wings distinct at base and apex (although overlap at base can give the impression that wings are continuous); ventral areole broadly ovate to rotund, 1–1.8 times as long as wide; otherwise resembling A. rigida, q.v.
Amorimia pubiflora (Adr. Juss.) W. R. Anderson—South-central Brazil (Minas Gerais, Goiás, Mato Grosso do Sul). Stems and inflorescence axis densely velutinous to glabrescent in age; lamina cordate or subcordate at base, originally densely velutinous on both sides, soon or eventually glabrescent above and below or the vesture persistent below, eglandular or bearing 1 or 2 pairs of tiny abaxial glands, well above base, set in 1–5 mm from margin; petiole 2–5 (–6) mm long, eglandular; stipules tiny, caducous; inflorescence elongated, many-flowered, open; bracts lanceolate and biglandular, bracteoles similar or elliptical, much smaller, often eglandular; pedicel 7–17 mm long, often inflated at apex; sepals revolute in anthesis; petals large (limb of lateral petals 8–12 mm long), abaxially densely velutinous over whole surface or at least on proximal half, adaxially glabrous or velutinous only on claw; anthers glabrous or velutinous on connective; styles dorsally truncate or acute to short-hooked at apex, the hook up to 0.7 mm long; samara velutinous on nut and wings or the wings glabrescent in age; lateral wings distinct at base and apex, the margin entire and rounded; dorsal wing 4–6 mm wide, widest toward apex but well-developed from base to apex, distinct at base and apex; ventral areole narrowly ovate.
Amorimia rigida (Adr. Juss.) W. R. Anderson—Bahia, Espírito Santo, Rio de Janeiro, and Minas Gerais, Brazil. Stems sericeous or tomentose to glabrate; leaves mostly opposite; lamina of larger leaves 5–12 (–14.5) cm long, 2.5–6.5 cm wide, cuneate at base, very soon quite glabrate, eglandular or (usually) biglandular well above base; petiole 2–10 mm long, eglandular; infloresence axis sericeous or tomentose; bracts lanceolate, biglandular, sessile or subsessile with the broad petiole up to 1 mm long; bracteoles like bracts but smaller and often eglandular; pedicel 3–8 mm long; sepals appressed in anthesis; petals small (limb of lateral petals 3–5 mm long), abaxially densely tightly tomentose over most of surface, adaxially densely tightly tomentose over distal 1/3–2/3 of limb; anthers usually with a basal tuft of hairs, and sometimes distal hairs as well; styles dorsally rounded or truncate at apex; samara 1.2–2.8 cm high, 2–3.7 cm wide, sericeous on nut and wings, the wings glabrescent at maturity; lateral wings distinct at base and apex, the margin entire or sinuate or erose; ventral areole narrowly elliptical or ovate, (2–) 2.2–3.5 times as long as wide.