Oxygonum atriplicifolium (Meisn.) Martelli

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

Habit

Trailing or ascending, annual or usually perennial herb, pubescent to densely tomentose

Stipules

Ochreae with 3–8 mm long setae at the margin

Leaves

Leaf-blade linear-lanceolate to narrowly triangular, entire to lobed, 1–3 x 0.3–1.8 cm, acute at the apex, cuneate to truncate or with a pair of short spreading lobes at the base, sparsely pubescent below to densely tomentose all over; petiole 3–15 mm long

Inflorescences

Inflorescences c. 8–30 cm long; fruiting pedicels exceeding the bracts by 4–6 mm, becoming recurved

Flowers

Flowers white, strongly heterostylous; perianth 3.5–4 mm long

Fruits

Fruits 1–2 to each bract, pendulous, 5–7.5 mm long, glabrous or pubescent, with 3 spreading prickles 1–3 mm long near the middle.

Distribution

C1, 2; S1–3; E Kenya, Mozambique, Madagascar

Ecology

Altitude up to c. 500 m.

Note

This species is very variable in Somalia, particularly as regards indumentum and leaf shape. Plants with broadly lobed leaves may resemble O. sinuatum, and plants with sagittate leaves (the normal shape in C2) have often been called O. sagittatum R. Graham (a species only known from northern Kenya). O. atriplicifolium differs from both O. sinuatum and O. sagittatum in its longer and recurved fruiting pedicels.

Flora Zambesiaca. Vol. 9, Part 3. Polygonaceae-Myriaceae. Pope GV, Polhill RM, Martins ES. 2006.

Type

Lectotype, chosen by Graham (1957), a cultivated plant from Calcutta Botanic Garden (probably from E Africa), Herb. Wallich 1719 (K, lectotype).

Flowers

Male flowers 5-lobed; lobes narrowly oblong, obtuse at the apex Flowers pedicellate, 1–3 in the axil of each bract, arranged in leafless spiciform terminal or axillary racemes up to 30 cm long or more; bracts up to 25 mm apart, 3–4 mm long, obliquely truncate, acute or acuminate with a fringe of setae at the apex; pedicels filiform, pubescent, those of hermaphrodite flowers lengthening to exceed the bracts by 4–6 mm, becoming patent and later reflexed; pedicels of male flowers not exceeding the bracts by more than c. 3 mm, withering, not lengthening or reflexed. Hermaphrodite flowers strongly heterostylous; perianths white or greenish outside, 5–6-lobed; lobes 1.5 mm long and broadly linear or ovate Flowers pedicellate, 1–3 in the axil of each bract, arranged in leafless spiciform terminal or axillary racemes up to 30 cm long or more; bracts up to 25 mm apart, 3–4 mm long, obliquely truncate, acute or acuminate with a fringe of setae at the apex; pedicels filiform, pubescent, those of hermaphrodite flowers lengthening to exceed the bracts by 4–6 mm, becoming patent and later reflexed; pedicels of male flowers not exceeding the bracts by more than c. 3 mm, withering, not lengthening or reflexed Male flowers 5-lobed; lobes narrowly oblong, obtuse at the apex. Hermaphrodite flowers strongly heterostylous; perianths white or greenish outside, 5–6-lobed; lobes 1.5 mm long and broadly linear or ovate.

Style

Styles of long-styled flowers 2 mm long and connate below for 0.75 mm; short-styled flowers not seen Styles of long-styled flowers 2 mm long and connate below for 0.75 mm; short-styled flowers not seen.

Fruits

Nut pendulous, 5–6.5(7) mm long, fusiform, trigonous, glabrous or pubescent, with 3 spreading prickles c. 1 mm long arising on the angles at or slightly below the middle. Nut pendulous, 5–6.5(7) mm long, fusiform, trigonous, glabrous or pubescent, with 3 spreading prickles c. 1 mm long arising on the angles at or slightly below the middle.

Ecology

Disturbed places, sandy soils.

Note

Forbes is not known to have collected plants from East Africa, but O. atriplicifolium is common around Mombasa and Malindi, and was collected there from the middle of the nineteenth century onwards, so this record from c. 1800, assumed to be from Mozambique according to a note by N.E. Brown on the herbarium sheet, may be incorrect.

Distribution

Also in Somalia, Madagascar and Kenya. Mozambique Without precise locality (“E coast of Africa”), Forbes s.n. (K).

Habit

A slender straggling or trailing annual or short-lived perennial herb. A slender straggling or trailing annual or short-lived perennial herb

Stem

Stems herbaceous, weak, reddish, up to 1 m long, much branched, longitudinally striate, glabrous to pubescent. Stems herbaceous, weak, reddish, up to 1 m long, much branched, longitudinally striate, glabrous to pubescent

Leaves

Leaves petiolate; lamina 2–3 × 1.5–1.8 cm, deltate to deltate-ovate or deltate-lanceolate, with the margins entire or slightly uneven but not deeply lobed, acute and sometimes ± aristate at the apex, truncate to cuneate at the base, rarely sagittate, glabrous on upper surface, pubescent on margins and veins of the undersurface, undersurface sometimes pustular; petiole 1–1.5 cm long, pubescent. Leaves petiolate; lamina 2–3 × 1.5–1.8 cm, deltate to deltate-ovate or deltate-lanceolate, with the margins entire or slightly uneven but not deeply lobed, acute and sometimes ± aristate at the apex, truncate to cuneate at the base, rarely sagittate, glabrous on upper surface, pubescent on margins and veins of the undersurface, undersurface sometimes pustular; petiole 1–1.5 cm long, pubescent

Ocrea

Ocrea light brown, membranous, up to 1 cm long, pubescent, truncate with a fringe of reddish-brown setae at the apex; setae may exceed ocrea tube in length. Ocrea light brown, membranous, up to 1 cm long, pubescent, truncate with a fringe of reddish-brown setae at the apex; setae may exceed ocrea tube in length

Male

Male flowers 5-lobed; lobes narrowly oblong, obtuse at the apex.

Hermaphrodite

Hermaphrodite flowers strongly heterostylous; perianths white or greenish outside, 5–6-lobed; lobes 1.5 mm long and broadly linear or ovate. Styles of long-styled flowers 2 mm long and connate below for 0.75 mm; short-styled flowers not seen.