8. Amaranthus hypochondriacus L. (Prince’s feather)
A. hybridus L. var. hypochondriacus (L.) B.L.
Rob.
Map 817
Plants
monoecious. Stems 30–250 cm long, erect or ascending, glabrous or sparsely to
moderately pubescent toward the tip with inconspicuous, mostly crinkled,
multicellular hairs, unarmed. Leaves long-petiolate. Leaf blades 2–15 cm long,
lanceolate to ovate or elliptic, narrowed or tapered to a sharply or rarely
bluntly pointed tip, narrowed or tapered at the base, the surfaces glabrous or
the undersurface sparsely pubescent mostly along the veins with inconspicuous,
mostly crinkled, multicellular hairs. Inflorescences usually red or yellow, less
commonly mostly bright green, axillary and terminal, the axillary
inflorescences short to long spikes, the terminal inflorescence usually a
panicle with few to many clusters of short to long, dense spikes (these
branching along mostly the lower half of the panicle axis), the flowers mostly
continuous along the spikes, the tip stiffly straight or nearly so, the main
axis and branches moderately pubescent with mostly crinkled, multicellular
hairs. Bracts 2.6–3.4 mm long, about as long as to slightly longer than the
fruits, lanceolate to ovate, narrowed or tapered to a sharply pointed tip, with
a moderately thickened green midrib and broad, thin, papery margins, the midrib
extending beyond the main body as a short awn, often somewhat spinelike at
maturity. Staminate flowers with (4)5 more or less similar sepals, these 3.0–3.3
mm long, straight, narrowly oblong to ovate, narrowed or tapered to a bluntly
or more commonly sharply pointed tip, usually with a minute, awnlike extension
of the midrib. Stamens 5. Pistillate flowers with (4)5 more or less similar
sepals, these 1.7–2.3 mm long, slightly and inconspicuously overlapping, more
or less straight at the tip, oblong-elliptic to ovate, bluntly to more commonly
pointed, usually with a short, awnlike extension of the midrib. Stigmas 3,
spreading from a thickened, erect base. Fruits 2.0–2.4 mm long, with
circumscissile dehiscence, the surface smooth or finely wrinkled when dry.
Seeds 1.0–1.3 mm in diameter, angled along the rim, the surface pale dark brown
to black or less commonly whitish yellow. 2n=32. July–October.
Introduced,
known thus far only from a single historical collection from Jackson County
(originated in Latin America, widely cultivated in tropical and warm-temperate
regions, escaping sporadically in the U.S.). Gardens and open, disturbed
areas.
As noted in the
treatment of A. cruentus, Steyermark’s (1963) original report of this
taxon was based on two Boone
County specimens that
subsequently were redetermined as A. cruentus. However, Costea et al.
(2001a) reported a new record from Jackson County, which Steyermark had
misdetermined earlier as A. caudatus. Amaranthus hypochondriacus is a
principal crop amaranth, one of the cultigens derived long ago in Latin
America, probably from selected strains of A. powellii or, more likely,
from hybrids between A. cruentus and A. powellii.