Boerhavia erecta, commonly known as the erect spiderling or the erect boerhavia, is one of more than 100 species in the genus Boerhavia. It is native to the United States, Mexico, Central America, Angola and western South America, but now is cosmopolitan in tropical and subtropical regions. In Africa its distribution extends from West Africa, eastwards to Somalia and down to South Africa. It has recently been found in parts of Madagascar and Réunion. In Asia, it occurs in India, Java, Malaysia, the Philippines, China and the Ryukyu Islands.
As an adventive species Boerhavia erecta is not widely regarded as a serious weed or invasive threat; in fact its physical and pharmacological attributes suggest that it is potentially useful.
Description
Boerhavia erecta has a chromosome number 2n=52. It is a perennial herb similar to Boerhavia diffusa, but can be distinguished by the fact that erect spiderlings are straight, bear white and pink flowers and bear obconic, glabrous fruit.
Boerhavia erecta plants can survive considerable damage from grazing and fire because their stems produce perennating buds near the ground surface.
Stems of B. erecta typically grow to about 60 centimetres (24 in) tall and 3–5 millimetres (0.12–0.20 in) across. They generally are cylindrical without furrows or ridges. In colour they are green, commonly tinted with purple, and towards their upper regions they are slightly pubescent, being covered in short, soft hairs. The base of the stem however, is glabrous and woody.
The leaves are somewhat fleshy. Their arrangement is opposite and unequal. Typically the leaf size ranges from 1.5–2.5 cm (0.59–0.98 in) long and 2–3.5 cm (0.79–1.38 in) wide to 3–4.5 cm (1.2–1.8 in) long and 2–3.5 cm (0.79–1.38 in) wide, with a petiole of roughly 2 cm (0.79 in) to 3 cm (1.2 in). The petioles of the leaf are pale green with a hint of purple. The blade of the leaf is...
