Persicaria salicifolia subsp. salicifolia

Global description

Persicaria salicifolia subsp. salicifolia is an herbaceous plant, glabrous or nearly so, upright, semi-decumbent or spreading. It is about 1 m tall. The leaves are simple, alternate, sessile or almost linear, lanceolate, pointed,  with smooth margin, glabrous or almost hairless. The ochrea is finished with long silks. The inflorescence is slender, consisting of several spike-like racemes bearing small, sparse, pink or white flowers. The fruit is a trigonal achene 2 mm long.

General habit

An erect or semi-decombant annual herb, sometimes spreading, which measures 90 cm to 1 m in height.

Underground system

The root is a taproot.

Stem

The stem is slender, smooth, cylindrical, marked by a succession of swollen nodes.

Leaf

The leaves are simple and alternate. The leaf is sessile to sub-sessile, linear-lanceolate, rather abruptly shrunken into a short petiole, pointed at the apex. It is 7.5 to 15 cm long and 1.5 cm wide. The blade is glabrous and smooth on both sides, sometimes slightly pubescent along the midrib and margin, that is entire. The ochrea, at the base of the petiole, is pubescent and long ciliated at the apex.

Inflorescence

The inflorescence is slender and loose consisting of a small number of spike-like racemes, 6-9 cm long, with sparse flowers. The racemes are borne by a hairless peduncle. The bracts are strongly hairy

Flower

The flower is sessile, pink and white consisting of a perianth with 5 rounded tepals, no gland, 6 to 8 stamens and usually 3 styles.

Fruit

The fruit is a trigonal achene with a pointed tip 2 mm long (shorter than the perianth), brown in color.

Worldwide distribution

Persicaria salicifolia subsp. salicifolia is a common species in Asutral and Tropical Africa. It is introduced and naturalised in Madagascar.