Trianthema portulacastrum L.
Family
Aizoaceae
Synonyms
Trianthema monogyna L.
Vernacular Names
|
English |
Horse purslane, carpet weed, giant pigweed. |
|
Indonesia |
Krokot, telekan (Java), krajep (Madura). |
|
Philippines |
Toston (Tagalog), ngatug (Ilokano), ayam (Bisaya). |
|
Cambodia |
Chonkuëng’ praëhs. |
|
Thailand |
Phakbia hin, phakkhom hin (Central). |
|
Vietnam |
C[or] tam kh[oo]i, d[af]n d[af]n. |
|
Papua New Guinea |
Pih-suh. |
|
French |
Pourpier courant |
Geographical Distributions
Trianthema portulacastrum is distributed throughout the tropics. It is found in Peninsular Malaysia, the Philippines, Java, Madura, Lesser Sunda Islands, the Moluccas, and Papua New Guinea.
Description
T. portulacastrum is an annual, succulent, prostrate or ascending herb, up to about 60 cm tall, often much branched, smooth or finely hairy and with a firm taproot. The branches are in the axil of the smaller leaf of the leaf pair. They are alternate.
The leaves are arranged opposite, ovate-obovate to obcordate-oblong, and measure 1-5 cm x 0.5-4.5 cm, where those of the same pair are very unequal in size. The margin is entire, purple or green. The petiole is 4-30 mm long, dilated and with sheath at the base. The pairwise connate into a funnel-shaped sheath. The stipules are small with one on each side of the petiole.
The inflorescence is a single flower in the leaf axils where the lower part is hidden by the pouch. The flowers are bisexual and actinomorphous. The sepals (perianth) are 5-lobed with the tube fused with the petiolar sheath, with 2 pointed bracteoles, and even with the stem. The obtuse lobes are with a long dorsal, subapical mucro, pale pink and rarely white. The petals are absent. There are 10-25 stamens, with white filaments and hairless. The ovary is superior, turbinate, truncate, with style 1.3 mm long and unilaterally stigmatose throughout its length.
The fruit is a capsule, measures 5 mm x 3 mm, partly exserted from the persistent perianth, truncate at apex, bilobed, with fleshy operculum, indehiscent and the basal part of capsule is thin-walled. There are 2-8 seeds, which are kidney-shaped, 1.5-2.5 mm long, with faint wavy ribs and black. The seedling is with epigeal germination.
Ecology / Cultivation
T. portulacastrum is a common weed in fields and in open, sunny localities such as roadsides, and often found on clayey soils near the sea, up to 200 m altitude. It is an aggressive weed, especially in Thailand, Australia and South America, and can be controlled either by uprooting the plants before flowering, or by spraying the herbicide Fernoxone.
Line Drawing / Photograph
References
- Plant Resources of South-East Asia No.12(2): Medicinal and poisonous plants 2.
