Wahlenbergia marginata (PROSEA)
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Introduction |
Wahlenbergia marginata (Thunberg) A.DC.
- Protologue: Monogr. Campan.: 143 (1830).
- Family: Campanulaceae
- Chromosome number: 2n= 18, 36, 54, 64, 72
Vernacular names
- Indonesia: angkeb, patikan (Javanese), jukut riut (Sundanese)
- Philippines: ligam (Igorot)
- Vietnam: sâm ruộng.
Origin and geographic distribution
W. marginata occurs in India, Sri Lanka, Burma (Myanmar), Indo-China, China, Taiwan, Japan, northern Thailand, the Malesian region except Peninsular Malaysia, Sumatra and Borneo, Australia and New Zealand. It is locally naturalized elsewhere, e.g. in the United States.
Uses
In Java W. marginata is used to treat skin diseases. In China and Indo-China, the roots are esteemed for the treatment of pulmonary afflictions such as cough and haemoptysis, and for the treatment of gastralgia.
Properties
A number of ionone-related and phenylpropanoid-derived glycosides have been isolated from an aqueous ethanol extract of the whole plant. In in-vitro testing, no activity was found against the human pathogenic fungi Aspergillus flavus , Candida albicans or Trichoderma viride .
Botany
A perennial herb 3-60 cm tall, glabrous or hairy, woody at base. Leaves arranged spirally, simple, linear to elliptical, 1.5-5.5 cm × 0.1-0.5 cm, decreasing in size upwards, serrate to almost entire, mostly sessile; stipules absent. Inflorescence a 1-few-flowered, terminal or axillary raceme, with small bracts. Flowers bisexual, regular, 3-5-merous, distinctly protandrous; pedicel 1-15 cm long; calyx lobes 0.8-4 mm long; corolla tube 1-5 mm long, lobes ovate or elliptical, 1-7 mm long, acute or acuminate, violet-blue or white; stamens alternating with corolla lobes, free; ovary inferior, obconical to bell-shaped, 1-5 mm long, 2-3-celled, style 1.5-5 mm long, stigma 2-3-lobed. Fruit an obconical to bell-shaped capsule 1.5-10 mm × 1-5 mm, 2-3-valved, many-seeded. Seeds ellipsoid to triangular, up to 1 mm long, shining.
W. marginata can be found flowering and fruiting throughout the year. Wahlenbergia comprises over 150 species and has an almost cosmopolitan distribution, the majority of species being found in the Southern hemisphere. In the Malesian region some 5 species occur, primarily at higher elevations. W. marginata is extremely variable with respect to its overall habit, and absolute and relative dimensions of nearly all floral parts.
Ecology
W. marginata appears to prefer a distinct seasonality, and is found in Malesia mainly in the mountains at 1000-3500 m altitude. It occurs in open Casuarina and Eucalyptus forest, but also on grassland, roadsides, and exposed rocks and old lava streams.
Management Hairy root cultures of W. marginata , infected with Agrobacterium rhizogenes , grew well in various hormonefree media and produced a high content of polyacetylenes, particularly the monoglucoside constituent lobetyolin.
Genetic resources
W. marginata is widespread and occurs in a wide range of often disturbed habitats, and is as such not threatened by genetic erosion. However, the genetic variability is remarkable and deserves more attention.
Prospects
Little is known about the pharmacological properties of W. marginata . Further research is needed to support its traditional medicinal uses. More research on the biosystematics of W. marginata is needed, as it is extremely widespread and variable, morphologically but also concerning chromosome number. The latter has been found a valuable tool for classification in New Zealand, resulting in a much narrower species concept than adopted here.
Literature
38, 181, 247, 334, 913.
Other selected sources
62, 621, 733, 734, 782.
Main genus page
Authors
R.P. Escobin
