Persicaria mitis (Schrank) Holub

Code

POLMT

Growth form

Broadleaf

Biological cycle

annual

Habitat

Marshland

Global description
 
Persicaria mitis is an annual, erect, semi-decumbent or prostrate herb, stem branching from the base and can reach up to 90 cm in height. The leaves are simple, alternate, lanceolate to ovate-lanceolate, tapered in tips at the apex and attenuated into a short petiole at the base. The ocrea is covered with small applied hairs and with long hairs on the edge. The flowers are arranged in slender spikes, more or less erect, 4 to 5 cm long; the perianth is without glands and without conspicuous veins, pink or white in colour. The fruit is a sleek and glossy alkene.
 
General habit
 
Persicaria mitis is an annual herb, erect or semi-decumbent, sometimes prostrate, reaching 90 cm in height.
 
Underground system
 
Taproot system.
 
Stem
 
The stem is cylindrical, erect or semi-decumbent, branching at the base, glabrous and smooth, with a succession of nodes, reaching 60 to 90cm in height.
 
Leaf
 
The leaves are simple and alternate, sessile to sub-sessile, oval-lanceolate to linear-lanceolate lamina, 4 to 12 cm long and 0.5 to 2 cm wide, attenuated in point at the apex and attenuated in a short petiole at the base. Both sides are glabrous and smooth, sometimes slightly pubescent along the midrib and on the margin. The ocrea at the base of the petiole is pubescent and extensively ciliate at apex.
 
Inflorescence
 
The inflorescence is a slender spike-like cluster, loose and slender, consisting of a small number of erect branches, 4 to 5 cm long.
 
Flower
 
The flowers are sessile, with pink, red or sometimes white perianth, without gland and without marked rib; 5 or 6 stamens, free ovary with 2-3 styles.
 
Fruit
 
The fruit is a trigonal, smooth and shiny achene, with pointed apex, about 2 mm long, brown in colour.

Madagascar: Persicaria mitis can bloom all year long if the soil is moist.

Persicaria mitis is an annual species that reproduces by seeds. They are spread by water, fruit-eating birds and humans.

Madagascar: Persicaria mitis grows on hydromorphic soils, moist alluvial soils rich enough, in sunny places or more or less shady. It is a weed of vegetable crops and pluvial rice or marshland with irrigation problem in semi-intensive cultural system. It is found on the banks of canals and rivers, in humid or marshy areas on the Highlands and at medium altitude (Middle-east, Highlands, Sambirano).
Mauritius: Absent.
Reunion: Absent.

Origin
 
Persicaria mitis is native to Eurasia.
 
Worldwide distribution
 
It is a species of global distribution: North America, Central and South America, Central and Southern Europe, Central Asia and West Africa, Madagascar, India and Pakistan, China, Japan, Asia southeast, Indonesia, Australia and the Pacific islands

Local harmfulness
 
Madagascar: Persicaria mitis is a weed infrequent and often in crops. It does not present any particular difficulty. It is a weed characteristic of humid areas, in vegetables crops and along rice fields of marshland and canals at medium altitude and on the Highlands. It can form small locally dense stands in canals and drains and on edges of vegetable cultivations on the Highlands and at medium altitude.
Mauritius: Absent.
Reunion: Absent.

Medicinal: Persicaria mitis is a medicinal plant used in traditional medicine in Madagascar to treat painful and infected wounds. This plant is also used as a decoction to treat fever with flu-like symptoms.

Herbarium pictures ReCOLNAT: https://explore.recolnat.org/search/botanique/simplequery=Persicaria%2520mitis