Lycium ferocissimum

Name and classification

Lycium ferocissimum Miers
Family Solanaceae

Common names

African boxthorn, boxthorn

Disseminule

seed

Description

Fruit a berry with numerous seeds. Seeds ovate, round or C- or D-shaped in outline, 2–2.5(2.7) mm long, 1.5–2.2 mm wide, 0.5–1 mm thick, variously dented or twisted from crowding, compressed, discoid, cross section oblong, +/– bent. Testa straw-colored, yellow, or amber to brown, glistening. Minutely reticulate, the walls of reticulations formed of fine, raised dots, but appears nearly smooth. Hilum conspicuous, in marginal notch, keyhole shaped, circular portion deeply sunken and surrounded by raised rim. Embryo linear-curved, seen twice in cross section; endosperm readily visible.

Identification considerations

Solanaceae seeds of moderate size (over 1.5 mm long) are often difficult to distinguish from one another. Characters that may aid in identification are size range, seed outline, surface reticulation (if visible), hilar shape, and embryo shape. Testa color is not a reliable character, as it may be affected by aging and length of time spent in a mature berry.

Compare with:

Solanum tampicense Dunal

Solanum torvum Swartz

Solanum viarum Dunal

Distribution

South Africa, Australia, New Zealand, and Tasmania

native to South Africa

Habitat

subhumid and semi-arid subtropical regions on drier soils; dry stream beds, roadsides, neglected areas

General information

Lycium ferocissimum is a spiny shrub ordinarily up to 5 m tall. In Australia it was originally cultivated as a hedge plant as it grows as an impenetrable, dense thicket, but has now become a widespread weed there. Animals avoid it because of its spines, which prevent them from reaching water sources and hinder grazing. This plant can also render roads impassible if it grows unchecked. Dispersal is by seeds alone, which are spread by animals that eat the fruits.

seeds

seeds

seeds

seeds

marginal view of seeds

marginal view of seeds

A, seed; B, longitudinal section of seed showing embryo; C, transection of seed; drawing by Lynda E. Chandler

A, seed; B, longitudinal section of seed showing embryo; C, transection of seed; drawing by Lynda E. Chandler

hilum of seed

hilum of seed

surface reticulation of seed

surface reticulation of seed

fruit

fruit