Amaranthus thunbergii Moq.

M. Thulin et al. Flora of Somalia Vol. 1-4 [updated 2008] https://plants.jstor.org/collection/FLOS

Morphology General Habit

Erect or ascending annual, 15–55(–100) cm

Morphology Stem

Stem slender to stout, simple or branched from the base upwards, glabrous or thinly hairy below, increasingly furnished above with long, multicellular, rather floccose hairs

Morphology Leaves

Leaves long-petiolate, narrowly or broadly elliptic to rhomboid or spathulate, sometimes purple-blotched blade, obtuse to retuse, glabrous or thinly pilose on the main nerves of the lower surface

Morphology Leaves Petiole

Petioles sometimes longer than the (5–)15–45(–60) x (4–)10–30(–40) mm

Morphology Reproductive morphology Flowers

Flower clusters all axillary, 6–15 mm in diam., increasingly distant below, male and female flowers intermixed

Morphology Reproductive morphology Flowers Tepal

Tepals 3, male and female ± similar, lanceolate to oblong or rarely narrowly spathulate, 3–6 mm, gradually or more abruptly narrowed to a long colourless awn

Morphology Reproductive morphology Flowers Gynoecium Stigma

Stigmas 3

Morphology Reproductive morphology Fruits

Capsule pyriform, c. 2.5–3.5 mm, with a short beak, circumscissile, obscurely wrinkled

Morphology Reproductive morphology Seeds

Seeds faintly reticulate, lenticular or slightly longer than wide.

Distribution

N1 throughout much of E and C tropical Africa S to Namibia and South Africa, introduced into Australia and hence to Europe as a casual alien.

Ecology

Altitude range 1100–1580 m.

Amaranthaceae, C. C. Townsend. Flora Zambesiaca 9:1. 1988

Morphology General Habit

Annual herb, ascending or erect, simple or branched from the base and frequently also above, reaching 15–55 cm.

Morphology Stem

Stem and branches stout, angular, glabrous or thinly hairy below, upwards increasingly furnished with long, crisped, multicellular, rather flocculent hairs.

Morphology Leaves

Leaves glabrous, or thinly pilose on the inferior surface of the primary venation, sometimes with a dark purple blotch, long-petiolate (petioles up to c. 4 cm. long, sometimes longer than the lamina), the lamina narrowly or broadly elliptic to rhomboid or spathulate, c. (5) 15–45 (60) × (4) 10–30 (40) mm., blunt or retuse at the apex with the midrib excurrent in a short mucro, at the base cuneate to attenuate, more or less decurrent along the petiole.

Morphology Reproductive morphology Flowers

Flowers green, males most frequent at the top of the upper clusters, all in axillary clusters 6–15 mm. across, approximate above, usually increasingly distant towards the base of the stem and branches with male and female flowers intermixed.

Morphology Reproductive morphology Inflorescences Bracts

Bracts and bracteoles deltoid-lanceolate, bracteoles subequalling or shorter than the perianth, pale-membranous, often greenish centrally above, the midrib often excurrent in a long, fine awn often as long as the basal portion, bracteoles shorter (to 2 mm. long), the awn colourless and often more or less reflexed above.

Morphology Reproductive morphology Flowers Perianth

Perianth segments 3, similar in male and female flowers, lanceolate to oblong, or in the females rarely narrowly spathulate, 3–6 mm., pale-membranous or (especially in the female flowers) somewhat greenish above, gradually or more abruptly narrowed into the long (0.75–1.5 mm.) awn formed by the excurrent midrib, the latter green but the divergent or flexuose awn colourless above; fruiting female perianth segments slightly accrescent, wider than those of the male flowers.

Morphology Reproductive morphology Flowers Gynoecium Stigma

Stigmas 3, flexuose or often reflexed, pale, 1.5–2 mm. long.

Morphology Reproductive morphology Fruits

Capsule ovoid-ellipsoid to pyriform, c. 2.5–3.5 mm. long, with a short beak, circumcissile, membranous, obscurely wrinkled, shorter than the perianth (attaining the base of the aristate apices).

Morphology Reproductive morphology Seeds

Seed 1–1.5 mm. across, black or chestnut, shining, feebly reticulate.

Amaranthaceae, C.C. Townsend. Flora of Tropical East Africa. 1985

Morphology General Habit

Annual herb, ascending or erect, simple or branched from the base and frequently also above, 15–55 cm.

Morphology Stem

Stem and branches stout, angular, glabrous or thinly hairy below, upwards increasingly furnished with long crisped multicellular rather flocculent hairs.

Morphology Leaves

Leaves glabrous or thinly pilose on the lower surface of the primary nervation, sometimes with a dark purple blotch, long-petiolate (petioles up to ± 4 cm., sometimes longer than the lamina); lamina narrowly or broadly elliptic to rhomboid or spathulate, ± (5–)15–45(–60) × (4–)10–30(–40) mm., blunt or retuse at the apex with the midrib excurrent in a short mucro, at the base cuneate to attenuate, ± decurrent along the petiole.

Morphology Reproductive morphology Flowers

Flowers green, ♂ flowers most frequent at the top of the upper clusters, all in axillary clusters 6–15 mm. in diameter, usually increasingly distant towards the base of the stem and branches, ♂ and ♀ flowers intermixed.

Morphology Reproductive morphology Inflorescences Bracts

Bracts and bracteoles deltoid-lanceolate, bracts subequalling or slightly exceeding the perianth, pale and membranous, often greenish centrally above, the midrib excurrent in a long fine awn often as long as the basal portion, bracteoles shorter (to 2 mm. long), awn colourless and ± reflexed above.

Morphology Reproductive morphology Flowers Perianth

Perianth-segments 3, similar in ♂ and ♀, lanceolate to oblong or rarely narrowly spathulate, 3–6 mm., pale and membranous or (especially in ♀) somewhat greenish above, gradually or more abruptly narrowed into the 0.75–1.5 mm. awn formed by the excurrent midrib, the latter green but the awn colourless above; fruiting perianth-segments slightly accrescent, wider than those of the ♂ flowers.

Morphology Reproductive morphology Flowers Gynoecium Stigma

Stigmas 3, flexuous or often reflexed, pale, 1.5–2 mm.

Morphology Reproductive morphology Fruits

Capsule pyriform with a short beak, ± 2.5–3.5 mm., circumscissile, membranous, obscurely wrinkled, shorter than the perianth (attaining ± the base of the aristate tips).

Morphology Reproductive morphology Seeds

Seed 1–1.5 mm., black or chestnut, shining, feebly reticulate, Fig. 4/3.

Habitat

Weed of cultivation, grazed grassland, grassland on rocky soil; 1100–1640 m.

Distribution

tropical Africa from Ethiopia and Somalia to Zaire and Angola, through to Namibia and South Africaintroduced into Australia and thence to Europe as a frequent casual wool adventive K4 T7 U1