Acalypha rhomboidea
Acalypha setosa
common three-seed-Mercury, rhombic copper-leaf, rhombic or common threeseed Mercury, ricinelle rhomboïde
Cuban copperleaf
usually erect, sometimes ascending, usually sparsely pubescent, rarely sparsely hirsute.
erect, sparsely pubescent.
petiole 0.4–7 cm;
blade ovate to broadly rhombic, 2–9 × 0.8–5 cm, base obtuse, margins crenate to serrate, apex acute to acuminate.
petiole 1–7 cm;
blade ovate, 2.5–10 × 1.5–8 cm, base broadly obtuse to rounded or truncate, margins serrate, apex acuminate.
bisexual, axillary;
peduncle 0.1–0.6 cm, pistillate portion 0.7–1.5(–2) × 1–2(–2.5) cm or pistillate bract solitary, staminate portion 0.3–1 cm;
allomorphic pistillate flowers rare, solitary in axils near base of stem.
unisexual, axillary (staminate) and terminal (pistillate; sometimes on short lateral branches, appearing axillary);
staminate peduncle 0.5–0.7 cm, fertile portion 0.5–1.5 cm;
pistillate peduncle 0.1–0.5 cm, fertile portion 3–12 × 0.7–1 cm;
allomorphic pistillate flowers common, near apices of pistillate inflorescences and mixed with flowers in staminate inflorescences.
of allomorphic flowers 1–2 mm.
of allomorphic flowers rudimentary.
pistil 3-carpellate (normal flowers), 1-carpellate (allomorphic flowers);
styles multifid or laciniate.
pistil 3-carpellate (normal flowers), 1(–3)-carpellate (allomorphic flowers);
styles multifid or laciniate.
smooth, pubescent;
allomorphic fruits obovoid, 2 × 1 mm, spiny, pubescent.
smooth, sparsely pubescent;
allomorphic fruits oblate ellipsoidal, longitudinally ridged, an irregular flange on each side, 1.4–1.7 × 1.5–2 mm, smooth, puberulent.
(1.2–)1.5–1.7(–2) mm, minutely pitted.
1.2–1.4 mm, minutely pitted.
bracts (normal flowers) loosely arranged to crowded (inflorescence axis clearly to scarcely visible between bracts) or solitary, 6–15 × 9–23 mm, abaxial surface sparsely pubescent and stipitate-glandular;
lobes (5–)7–9(–11), lanceolate to triangular, 1/3–2/3 bract length;
bracts of allomorphic flowers absent.
bracts (normal flowers) loosely arranged (inflorescence axis visible between bracts), 5–7 × 3–4 mm, abaxial surface glabrous;
lobes 7–9(–13), linear, nearly bract length, muricate; of allomorphic flowers on pistillate inflorescences like those of normal flowers, on staminate inflorescences absent.
Acalypha rhomboidea
Acalypha setosa
Acalypha rhomboidea often has been called A. virginica due to controversy about the typification of that name. Conservation of the type of A. virginica resolved the issue. This nomenclatural problem, combined with use of inappropriate characters to distinguish A. rhomboidea and A. virginica, has resulted in considerable confusion between these amply distinct species. The two can be distinguished most readily by the pistillate bracts, which are clearly hirsute abaxially in A. virginica but sparsely pubescent abaxially in A. rhomboidea. In addition, the bracts of A. virginica have (8–)10–14(–16) triangular lobes one fourth to one half the bract length, whereas those of A. rhomboidea have (5–)7–9(–11) lanceolate or triangular lobes one third to two thirds the bract length, and the stems of A. virginica usually are hirsute whereas the stems of A. rhomboidea are rarely so.
In the southern part of its range, many Acalypha rhomboidea plants have been confused with A. gracilens. These plants are more delicate than A. rhomboidea from farther north, with notably smaller pistillate bracts, and they usually produce allomorphic flowers, whereas more robust or northerly plants rarely do. They can be distinguished from A. gracilens by having relatively wider leaves and pistillate bracts with fewer lobes and no red sessile glands.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Acalypha setosa, indigenous from Mexico to northern South America and the West Indies, was first introduced to the United States in the late 1800s and now occurs sporadically through the southeastern states.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Go Botany
IL Wildflowers
KS Wildflowers
LA Plants
MD Biodiversity
MI Flora
MN Wildflowers
MO Plants
WildflowerSearch
iNaturalist
USDA Plants Database
