Flemingia (PROSEA)

Plant Resources of South-East Asia Introduction

List of species

Flemingia Roxb. ex W.T. Aiton

Protologue: Hort. Kew., ed. 2, 4: 349 (1812).

Family: Leguminosae

Chromosome number: x = 10, 11; F. grahamiana, F. macrophylla, F. stricta: 2n= 22

• Flemingia macrophylla (Willd.) Merr.,
• F. strobilifera (L.) Roxb. ex W.T. Aiton.

Flemingia comprises about 40-50 species in the tropical regions of South and South-East Asia and Australia, and two species occur naturally in Africa. F. macrophylla and F. strobilifera have been introduced in Africa and the Americas as cover, hedge and mulch crop.

In Indonesia, the leaves of F. lineata (L.) Roxb. ex W.T. Aiton are used in traditional medicine. The leaves of F. stricta Roxb. ex W.T. Aiton, from West Java, Indo-China, Thailand and Burma (Myanmar), are used in Cambodia to treat scabies. A decoction of the tuber F. vestita Benth. ex Baker found from India eastward to southern China, is used in India as a vermifuge. In India, F. grahamiana Wight & Arn. is used externally for skin diseases and internally as a purgative and specific for colds. F. grahamiana and F. macrophylla are the principal sources of the resinous powder known as "waras" or "warrus". "Waras" is a coarse purple or orange-brown powder, consisting of the glandular hairs rubbed from the dry pods, principally used for dyeing silk; the active compound is called flemingin. In Arabia, it is employed as a cosmetic, anthelmintic and a remedy for coughs and chills. F. macrophylla , F. stricta and F. strobilifera are minor hosts of the Indian and Chinese lac insects. F. macrophylla is an important hedge plant and forage crop in various parts of the tropics. Various other Flemingia species are likewise used as a forage or green manure.

Phytochemical analysis revealed the presence of some general compounds e.g. quercetin, rutin and quercimetrin in the leaves, flowers and stems, and phloridzin (2-phloretin-β-glucoside) and naringin (naringenin-5-rhamno-glucoside) in the leaves of F. strobilifera. Four isoflavones (genistein, formononetin, pseudobaptigenin and daidzein) have been isolated from the outer tissues of the tuber of F. procumbens. Flavonoids, fleminone and flemiphyllin were isolated from F. macrophylla , while flamiflavone, flemistrictin, myricitrin, noringenin, quercetin, genistin were isolated from the leaves and roots of F. stricta.

The in vitro activity of tuber peel extract of F. procumbens was tested against helminth parasites. Live nematodes (Ascaris suum, A. lumbricoides, Ascaridia galli and Heterakis gallinarum), cestodes (Raillietina echinobothrida) and trematodes (Paramphistomum sp.) were collected in physiological buffered saline (PBS) and maintained at 37 ± 1°C. In vitro treatment of the parasites with the crude plant extract (50 mg/ml) in PBS revealed complete immobilization of the trematodes and cestodes in about 43 and 20 minutes, respectively. However, the cuticle-covered nematodes did not show any changes in physical activity and remained viable even after a long period of exposure to the extract. Exposure of R. echinobothrida to genistein (0.5 mg/ml), an active principle isolated from the tuber peel, caused spontaneous loss of movement (paralysis) in 4.5 h, which was slower than the time required for the reference drug praziquantel (0.01 mg/ml). The treated parasites showed structural alterations in their tegumental structure. The results indicate that F. procumbens tuber peel extract has anthelmintic properties against cestodes and trematodes.

The 70% ethanol extract of the roots of F. prostrata Roxb. (synonym: F. philippinensis Merr. & Rolfe), from the Philippines, Taiwan, China and India, showed cytotoxic activity against a P-388 lymphocytic leukaemia cell culture. In addition, two prenylated isoflavones, flemiphilippinins A and B, were isolated from the roots and showed significant cytotoxicity in vitro.

• Perennial herbs, subshrubs or shrubs, mostly erect.
• Leaves alternate, 3-foliolate, sometimes 1-foliolate; stipules caducous; leaflets ovate to lanceolate, with vesicular glands below; stipels absent.
• Inflorescence an axillary or terminal spike, raceme or panicle, sometimes crowded and head-like or few-flowered, bracts large or small, persistent or caducous, bracteoles rarely present.
• Calyx 5-lobed, glandular; corolla slightly larger than the calyx, standard elliptical or orbicular, short-clawed pink, red or purple, often mixed with green or yellow; androecium diadelphous, adaxial stamen free; ovary subsessile, 2-ovuled.
• Fruit a pod, oblong, 6-12 mm long, inflated, dehiscent, 2-seeded.
• Seed globose, brown or black.

The tuber bearing Flemingia vestita is often incorrectly considered as synonym of F. procumbens Roxb. an essentialy non-tuberous species. A thorough taxonomical revision of the entire genus is due, especially the status of the many synonyms at times given to F. macrophylla deserves attention. Several new species have been described in the course of time, even just in the context of local Floras (between 1980 and 1999).

F. lineata, F. macrophylla and F. strobilifera flower and fruit throughout the year in Indonesia. F. lineata, F. macrophylla, F. prostrata (synonym: F. philippinensis) and F. strobilifera have nodulating ability and fix atmospheric nitrogen.

Flemingia species are normally propagated by seed. Scarification of the seed is usually required to increase the germination percentage. F. macrophylla and F. strobilifera can also be propagated by cuttings.

Leaves and branches of Flemingia are collected whenever the need arises. Whole plants are uprooted to obtain the tubers.

Leaves and roots of Flemingia can be used fresh, or dried for storage and later use.

Germplasm collections of the important forage crops include F. macrophylla. Flemingia species do not seem to be particularly threatened or at risk of genetic erosion in view of their preference for disturbed habitats.

The activity of tuber peel extracts of F. vestita on helminth parasites is interesting, and merits further research in order to fully evaluate the potential of compounds such as genistein as lead compounds for development of future anthelmintics.

• Budelman, A. & Siregar, M.E., 1997. Flemingia macrophylla (Willd.) Merrill. In: Faridah Hanum, I. & van der Maesen, L.J.G. (Editors): Plant Resources of South-East Asia No 11. Auxiliary plants. Backhuys Publishers, Leiden, the Netherlands. pp. 144-147.
• Chen, M., Lou, S.Q. & Chen, J.H., 1991. Two isoflavones from Flemingia philippinensis. Phytochemistry 30(11): 3842-3844.
• Nguyen Van Thuan, 1979. Légumineuses-Paplionoïdées Phaséolées [Leguminosae-Papilionoideae Phaseoleae]. In: Vidal, J.E. & Vidal, Y.(Editors): Flore du Cambodge, du Laos et du Viêtnam [Flora of Cambodia, Laos and Vietnam]. Vol. 17. Muséum National d'Histoire Naturelle, Paris, France. pp. 138-155.
• Rao, H.S.P. & Reddy, K.S., 1991. Isoflavones from Flemingia vestita. Fitoterapia 62(5): 458.
• Saxena, V.K., Nigam, S.S. & Singh, R.B., 1976. Glycoside principles from the leaves of Flemengia [Flemingia] strobilifera. Planta Medica 29(1): 94-97.
• Tandon, V., Pal, P., Roy, B., Rao, H.S.P. & Reddy, K.S., 1997. In vitro anthelmintic activity of root-tuber extract of Flemingia vestita, an indigenous plant in Shillong, India. Parasitology Research 83(5): 492-498.

• L.J.G. van der Maesen