Articles

Pilea microphylla (L.) Liebm.

Pilea microphylla (L.) Liebm.

Family

Urticaceae

Synonyms

Pilea muscosa Lindley.

Vernacular Names

English Artillery plant, gunpowder plant.
Indonesia Katumpangan (Jakarta), akar nasi, jalu-jalu bobudo (Moluccas).
Philippines Alabong (Igorot).
Vietnam Ph[as]o b[oo]ng, l[aw]n t[aw]n.

Geographical Distributions

Pilea microphylla originates from South and Central America, but has escaped from cultivation and is widely spread in other tropical and subtropical regions, e.g. in Africa, Madagascar and Asia. In Southeast Asia, it is naturalised, e.g. long since in Java, and also in towns in Peninsular Malaysia and the Philippines, but also elsewhere. In temperate regions, it is a greenhouse weed, but locally, e.g. in the United States, it occurs persistently outdoors in flowerbeds and lawns.

Description

Pilea microphylla is a small, monoecious, annual or short-lived perennial herb which can grow up to 30 cm tall, but usually smaller, often much-branched and forming mats. The stems are drooping or ascending when older, juicy and usually smooth. Short side-shoots are often present in leaf axils.

The leaves are arranged opposite, but the leaves of a pair are of very unequal size, simple and generally entire, obovate to elliptical or ovate, measuring 1-15 mm x 0.5-4 mm, rounded to wedge-shaped at base, rounded to obtuse at apex, hairless, with prominent cystoliths above and indistinctly veined. The petiole is 0.5-6 mm long. The stipules are minute and caducous.

The inflorescence is an axillary, small, cymose cluster, which is 1-4 mm long, sessile or with stalk, usually with a few male and 5-10 female flowers. The flowers are unisexual, small, 3-merous and subsessile. The male flowers are with subequal perianth segments and 3 stamens while the female flowers are with unequal perianth segments, superior and with 1-celled ovary.

The fruit is ovoid, 1-seeded, 0.5-1 mm long, smooth and brown.

Ecology / Cultivation

Pilea microphylla occurs on old walls, dams, roads and pathways while in Java up to 1400 m altitude.

Line Drawing / Photograph

Pilea_microphylla_L_Liebm

References

  1. Plant Resources of South-East Asia No.12(3): Medicinal and poisonous plants 3.