Erechtites (PROSEA)

Plant Resources of South-East Asia Introduction

List of species

Erechtites Rafin.

Protologue: Fl. Ludovic.: 65 (1817).

Family: Compositae

Chromosome number: x= 10; 2n= 40 (both species).

Major species and synonyms

• Erechtites hieracifolia (L.) Rafin. ex DC., Prodromus 6: 294 (1838), synonym: Senecio hieracifolius L. (1753).

• Erechtites valerianaefolia (Wolf) DC., Prodromus 6: 294 (1838), synonym: Senecio valerianaefolius Wolf (1825).

Vernacular names

• Pilewort, Malayan groundsel (En)
• Fireweed (Am)
• Indonesia: sintrong (Sunda), bolostrok (Sunda), jambrong (Sunda)
• Philippines: hagalpohansaw (Bisaya), doyan-doyan (Bukidnon), salimbego (Marinduque)
• Thailand: phakkat-nokkut (central).

Origin and geographic distribution

• E. hieracifolia is native to the more humid parts of North and South America. It is adventitious in Central Europe, Hawaii and South-East Asia. It does not occur in Africa, the Near East, Australia or the Pacific islands.

• E. valerianaefolia is native to tropical and subtropical America and adventitious in many other tropical areas including South-East Asia, southern China, Australia and the Pacific islands, but does not occur in Africa.

Uses

The young tops of pilewort, including young flower heads, are much relished in Java as a vegetable, mostly eaten raw with rice and a sauce of ground hot capsicum peppers. They can also be consumed after being steamed, but this method is rarely encountered because the cooking makes the leaves very soft. It is believed that consumption of pilewort improves the milk production of women after childbirth. In the New World, E. hieracifolia is only used medicinally to dispel fever and as a cough remedy. In the United States, it was formerly given as an emetic, alterative, cathartic and acrid tonic and used as an astringent. Pilewort is cut in Indonesia as fodder for small ruminants, and is considered a good cattle feed in Australia.

Production and international trade

Leaves of pilewort are sold locally and are occasionally found in West Javanese markets. Tops are harvested directly from the wild and there are no records of cultivation.

Properties

No data on the nutritive value are available. Related to the medicinal properties, E. hieracifolia contains several alkaloids, two of which have been identified as seneciphylline and senecionine.

Description

• Erect annual or perennial herbs, succulent, up to 2 m tall.
• Stems ribbed, simple or much branched in upper half, fleshy, variously pubescent.
• Leaves alternate, sessile or petiolate, very variable in size, form, hairiness and degree of incision.
• Inflorescences are heads, campanulate-cylindrical, heterogamous, arranged in terminal corymbs; involucre uniseriate, cylindrical, consisting of a whorl of lanceolate, acute bracts at first coherent and erect, finally separating and reflexed, with dark-coloured central band, and a few lower bracts, much smaller, free; receptacle flat or cup-shaped, naked; ligulate flowers absent; marginal flowers (florets) 1-many seriate, female, with filiform, 3-5-dentate corolla; central flowers (disk florets) numerous, bisexual, with tubular-filiform corolla ending in funnel-shaped, 4-5-dentate limb; style-arms long, with crown of divergent hairs surrounding appendage of fused papillose hairs.
• Fruits linear achenes, ribbed; pappus hairs numerous, thin, dentate.

E. hieracifolia.

• Annual herb, up to 2 m tall.
• Leaves sessile, or if shortly petiolate, then petiole conspicuously alate, lanceolate or oblong-lanceolate, 3-30 cm × 0.5-7 cm, lower ones with a narrowed, higher ones with a broad, truncate or auricled base; higher ones coarsely dentate-pinnately lobed.
• Peduncle up to 6 cm long; flower head 12-15 mm × 6-8 mm, diameter always about half its length; involucre 10-12 mm long; flowers light yellow; marginal florets bi- or pluriseriate.
• Achenes ca. 2.5 mm long, brown, with entirely white, 8-12 mm long pappus.

E. valerianaefolia.

• Annual herb, up to 2 m tall.
• Leaves petiolate or inconspicuously alate at base; petiole 0.5-4 cm long; leaf-blade oblong, pinnately lobed to pinnatipartite, 4-18 cm × 2-9 cm.
• Peduncle up to 5 cm long; flower head 10-15 mm × 3-5 mm, diameter always less than one-third of its length; involucre 8-10 mm long; flowers light violet; marginal florets uniseriate or subbiseriate.
• Achenes ca. 3 mm long, brown, with reddish, 8-10 mm long pappus.

Growth and development

Both species are found on recently disturbed areas in forest zones, and also as weeds in crops. They grow in abundance due to their easy establishment and the production of a large number of viable seeds which are easily dispersed by wind. They flower and fruit year-round.

Other botanical information

Three varieties are distinguished within E. hieracifolia, mainly on the basis of the length of the bracts on the peduncle and of the free bracts of the involucre. According to this, all South-East Asian plants belong to var. cacalioides (Fischer ex Sprengel) Grisebach with bracts on the peduncle as long as the involucre and the free bracts longer than 1/4 of the length of the involucre; those bracts are also ciliolate with multicellular hairs.

The reputation of E. hieracifolia as a pantropical weed rests largely on confusion with Crassocephalum crepidioides (Benth.) S. Moore. C. crepidioides has longer style-arm appendages, dark red achenes, lyrately pinnatifid and petiolate lower leaves, usually lacking pistillate marginal florets, and florets often pink. It is native to Africa.

E. valerianaefolia is sometimes subdivided into four botanical forms based on foliage differences, but intermediate forms occur, so this subdivision is difficult in practice.

E. hieracifolia and E. valerianaefolia are often confused. The major differences are: pappus white in E. hieracifolia, reddish in E. valerianaefolia; leaves sessile versus petiolate; diameter flower head about 1/2 its length versus less than 1/3 its length; marginal florets bi- or pluriseriate versus uni- or sub-biseriate. In tropical America the species sometimes hybridize. In West Java the two species are not clearly discriminated by their vernacular names.

Ecology

Both Erechtites species thrive in sunny, rather moist localities, on roadsides, in recent clearings and on waste sites, often becoming common but tolerable weeds in estate crop plantations. They are among the early colonizers in newly cleared areas, especially after burning (fireweed). They occur in the lowlands as well as in the mountains up to 2200 m altitude. Their presence in quantity is usually considered an indication of a very fertile topsoil.

Agronomy

Pileworts are not cultivated. As companion weeds of crops, they are always readily available. They are often spared during selective weeding.

Genetic resources and breeding

No germplasm collections of pileworts are available.

Prospects

Pilewort is considered as a weed in all areas where it occurs, and activities are directed more towards its eradication than towards its propagation. It is worthwhile investigating its nutritional value and promoting its use as a vegetable.

Literature

• Backer, C.A. & van Slooten, D.F., 1924. Geïllustreerd handboek der Javaansche theeonkruiden en hunne betekenis voor de cultuur [Illustrated handbook of weeds of Javanese tea plantations and their significance for tea-growing]. Ruygrok, Batavia, Dutch East Indies. Figs. 232 & 233.
• Belcher, R.O., 1956. A revision of the genus Erechtites (Compositae) with inquiries into Senecio and Arrhenechthites. Annals of the Missouri Botanical Garden 43: 1-85.
• Morton, J.F., 1981. Atlas of medicinal plants of Middle America (Bahamas to Yucatan). C.C. Thomas Publisher, Springfield, Illinois, United States. pp. 927-928.
• Ochse, J.J. & Bakhuizen van den Brink, R.C., 1980. Vegetables of the Dutch East Indies. 3rd English edition (translation of "Indische Groenten", 1931). Asher & Co., Amsterdam, the Netherlands. pp. 132-134.
• Wee, Y.C., 1970. Weed succession observations on arable peat land. The Malayan Forester 33: 63-69.

Authors

• M.A. Rifai