Pilea microphylla (L.) Liebm.

Code

PILMI

Growth form

Broadleaf

Biological cycle

Annual

Habitat

Terrestrial

Global description

Pilea microphylla is a small herbaceous plant, monoecious (male and female flowers separate on the same tree), prostrate or in small erect tuft, reaching 40 cm in height. The entire plant is quite fleshy, dense and abundantly branched. The stem is cylindrical, with cystoliths. The leaves are numerous, simple, entire, opposite, unequal in the same pair. They are sub-sessile, with elliptical to sub-orbicular lamina, less than 5 mm long, with linear cystoliths. The inflorescences are small, compact globular cymes at the axils of the leaves, solitary or in pairs, shorter than the leaves. Male and female flowers very small reduced, distinct.
 
Growth habit
 
Small plant with fleshy appearance, prostrate or erect, profusely branched from the base, 2 to 40 cm high.
 
Underground system
 
Taproot
  
Stem
 
The stem is cylindrical, fleshy, glabrous, highly branched and bearing linear cyctolithes. It is light green in color, more or less translucent.
 
Leaf
 
The leaves are simple, opposite, very unequal in size in the same pair. They are sub-sessile or very shortly petiolate (petiole of 0.1 to 4 mm in length). At the base are tiny stipules, hyaline, glabrous and quickly deciduous. The lamina is entire elliptical to sub-orbicular, 2 to 5 mm long (up to 12 mm for the largest) and 1 to 6 mm wide. The base is wedged and the apex is wedged to rounded, margin is entire. The lamina is fleshy, green, glabrous on both sides, with linear cystoliths arranged more or less transversely on the upper side. Additional leaves often develop from axillary buds, which increases the dense appearance of plant.
 
Inflorescence
 
The inflorescences are small globular cymes, very shortly pedunculate, in the axils of the leaves, solitary or in pairs and smaller than the leaves.
 
Flowers
 
Female flowers very small, greenish, measure 0.4 to 0.7 mm in diameter and are sessile. Male flowers reduced and greenish, 0.3 to 1.1 mm in diameter and are borne on short pedicel of 0.1 to 0.5 mm long.
 
Fruit
 
The fruit is an alkene, 0.5 to 0.7 mm long.
 

Pilea microphylla flowers throughout the year.

Mayotte: Pilea microphylla flowers and fruits all year round.

 

Pilea microphylla is an annual species. It is propagated by seeds.

Origin

Pilea microphylla is native to the Caribbean and Central America and northern prt of South America

Worldwide distribution

A species introduced throughout tropical South America, West and Central Africa, naturalized in the Mascarene Islands (Reunion, Mauritius), India, and in South East Asia, New Caledonia.

French Guiana: It is a rather frequent plant in the zones of vegetable crops under greenhouse, in edge of the ditches of drainage, it goes up sometimes on the mound of culture and can form very dense spots.
Mauritius: Pilea microphylla is a weed species that can be very troublesome and abundant in culture pots in nurseries.
Reunion: The species was not seen as a weed of crops.

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