Malayan Nature Journal 2010, 62(3), 241-248 Cabombaceae, a new family record for Peninsular Malaysia M.Y. SITI-MUNIRAH¹ and M.Y. CHEW Although the aquatic plants, Cabomba aquatica Aubl. and C. furcata Schultes & Schultes f. (Cabombaceae), are now well-established in Peninsular Malaysia, they have not formally been recognized as a family new to the flora of Peninsular Malaysia. Cabomba furcata is more widespread and is already a serious alien water weed in Tasik Chini, Pahang, where local people call it ekor kucing. Cabomba aquatica is not so widespread. Both species are potentially invasive and threaten the ecology of open, slow-flowing water bodies. Keywords. Cabomba aquatica, C. furcata, noxious water weeds. INTRODUCTION During a recent botanical survey of the Sedili Kechil area, Johor, a water plant with submerged, reddish, feathery fan-leaves and pretty pink-purple flowers like miniature waterlilies was encountered growing in shallow, slow-flowing water. It grew in full sun, as well as in deeply shaded areas, and formed large masses over extensive areas. It proved to be Cabomba furcata Schultes & Schultes f. (Fig. 2), Cabombaceae, the forked fanwort or pink Cabomba. It is native in tropical and subtropical South America and the West Indies. It is surprising that this family has not previously been reported in the taxonomic literature as naturalized in Peninsular Malaysia because it is so well-established in Tasik Chini that it has seriously impacted the tourist value of the lake and has been given a local name, ekor kuching (cat’s tail). A second species, C. aquatica Aubl. (Fig. 1), is also naturalized but is less common. Neither has been reported as naturalized in other countries in SE Asia or Malesia. Ørgaard (1991) reported C. caroliniana A.Gray from ‘Malaysia’, but this is an error for Malesia because the record is from Papua New Guinea. The Cabombaceae are aquatic plants grouped into two genera: Brasenia with a single species, B. schreberi J.Gmelin that is widespread from tropical America, Africa, India, temperate E Asia and Australia; and Cabomba with five species from South America, southern North America and the West Indies (Mabberley, 2008). The family is closely related to the waterlilies, Nymphaeaceae, with which 1 Forest Research Institute Malaysia, 52109 Kepong, Selangor, Malaysia. sitimunirah@frim.gov.my Manuscript received: 5 Jan 2010 Manuscript accepted: 10 Feb 2010. 241 it shares the aquatic habit, floating peltate or subpeltate leaves and solitary waterlilylike flowers but it is distinguished from that family by its free, few-seeded carpels. TAXONOMY Cabombaceae A.Rich. Nouv. Elém. Bot. 4 (1828) 420; Heywood in Heywood et al., Flow. Pl. Fam. World. (2007) 77; Mabberley, Pl. Book, 3rd ed. (2008) 132; Williamson & Schneider in Kubitzki, Fam. Gen. Vasc. Pl. 2 (1993) 157. Aquatic perennial herbs, rhizomes rooted in mud, stems submerged. Floating leaves peltate, lamina linear-elliptic to elliptic-oval, entire; in Cabomba also with submerged finely divided leaves. Flowers solitary, regular, bisexual, axillary, trimerous; sepals (2–)3, free; petals 3, free, clawed at base; stamens 3–6 (Cabomba), 18–36 (Brasenia); ovary superior, carpels free, 1–4 (Cabomba), 4–18 (Brasenia). Fruits achene-like (Brasenia) or follicle-like (Cabomba). Seeds 1–3(–5), endosperm scant, perisperm copious. Brasenia is different from Cabomba in that it does not produce opposite or whorled dissected submerged leaves, only alternate entire floating leaves, and its flowers have sepals that are not petaloid, with many more stamens and more carpels, and it produces achene-like fruits. Cabomba Aubl. Pl. Guian. 1 (1775) 321, t. 124; Ørgaard, Nord. J. Bot. 11 (1991) 194; Williamson & Schneider in Kubitzki, Fam. Gen. Vasc. Pl. 2 (1993) 160. Submerged aquatic plants, rhizomes rooted in mud. stems submerged, depending on water depth growing to 3–4 m. Leaves heteromorphic, opposite or whorled submerged leaves fan-like, palmately dissected several times into filiform segments; alternate floating peltate leaves produced on flowering shoots entire, linear-elliptic to elliptic-ovate. Flowers raised 2–4 cm above the water surface, white, yellow or purple; sepals petaloid; stamens 3–6. Fruits follicle-like, indehiscent and disintegrating when ripe. Key to Species in Malaysia Lamina of peltate floating leaves broadly elliptic, 4–15 mm wide; flowers bright yellow ................................................................................................................................ 1. C. aquatica Lamina of peltate floating leaves narrowly elliptic, c. 3 mm wide; flowers pink-purple .................................................................................................................................. 2. C. furcata 242 Figure 1. Habitat and habit of Cabomba aquatica. 243 1. Cabomba aquatica Aubl. (Fig. 1, 3A1–3). Pl. Guian. 1 (1775) 321 t. 124; Ørgaard, Nordic J. Bot. 11 (1991) 194. Basionym: Nectris aquatica (Aubl.), Willdenow, Sp. Pl. ed. 2, 1 (1799) 248, Type: The name is typified by plate 124 in Aublet, Hist. pl. Guiane (1775). Stems grass- to olive-green. Submerged filiform leaves green, opposite; petiole 3– 8 mm long; lamina divisions three dimensional, terminal divisions narrow and linear, 15–30 mm long. Floating peltate leaves green above, often deep magenta beneath, raised to the surface of water by a thick petiole, c. 7–35 mm long; lamina broadly elliptic to oval, 5–20 × 4–15 mm, margin entire. Pedicels hairy, 2–4 cm long. Flowers bright yellow, 8–10 mm in diameter, c. 7 mm long; sepals obovate, c. 7 × 3 mm, reddish-tinged at base; petals ovate-oblong, c. 7 × 2–3 mm, base extended into two equal, straight semi-ovate lobes with two elliptic, yellow-orange patches, apex truncate-obtuse or rarely emarginate; stamens bright yellow; carpels 2, divergent at maturity, with 1–4 ovules each. Seeds black, ovoid-ellipsoid, 2–3.5 × 1.5–2.5 mm broad, surface verrucate. Distribution. South America (Brazil, French Guiana, Surinam, Guyana, Venezuela and Colombia). In Peninsular Malaysia, naturalized in Sungai Mati, Muar, Johor. Ecology. Found in both stagnant and slow-moving water, in fully exposed conditions. It is free-floating as well as rooted. Specimen examined. Johor, Muar, Sg. Mati Siti Munirah et al. FRI 67982 September 2009 (KEP). Uses. Sold as oxygenating aquarium plants (Williamson & Schneider 1993). Figure 2. Habitat and habit of Cabomba furcata. 244 Figure 2. Habitat and habit of Cabomba furcata. Figure 3. A: Cabomba aquatica. B: Camboba furcata 1, flower. 2, submerged filiform leaves. 3, floating peltate leaves. 245 Figure 3. A: Cabomba aquatica. B: Camboba furcata 1, flower. 2, submerged filiform leaves. 3, floating peltate leaves. 2. Cabomba furcata Schultes & Schultes f. (Fig. 2, 3B1–3) in Roem. & Schultes, Syst. Veg. 7,2 (1830) 1379; Ørgaard, Nordic J. Bot. 11 (1991) 196; Type: Leandro 8 Brasilia, 1821 (lectotype M, n.v.). Stems olive-green to reddish brown. Submerged filiform leaves dark purple, in whorls of three, at the apex often opposite; petiole c. 1–2 cm, lamina with linear divisions in one plane, c. 4 cm long. Floating peltate leaves olive-green, sometimes with a dark purple margin, lamina narrowly rhombic or linear to lanceolate, occasionally sagittate, 20–40 mm × 3 mm. Pedicels 2–5.5 cm long. Flowers purplish, 6–12 mm diameter, 5–10 mm long; sepals obovate-elliptic, 5–9 × 2–4 mm, apex obcordate, basal third yellow, distal two thirds purplish red to bluish violet with darker veins, with a darker rim at margin; petals ovate-oblong, 5–9 × 2–5 mm, base slightly auriculate, the lobes with two yellow, confluent patches, the claw whitish; stamens greenish yellow, 5 mm, anthers yellow; carpels 2, divergent at maturity. Seeds globose, 1–2 mm diameter, echinate, surface verrucate. 246 Distribution. South America (Brazil, Bolivia, Colombia, Ecuador, Guyana, Peru and Venezuela) and the West Indies (Costa Rica, Cuba and Trinidad). In Peninsular Malaysia, naturalized in Johor (Sg. Sedili Kechil and Sg. Mati), Pahang (Tasik Chini), Penang (stream from recreation forest and rice field, Taman Rimba Telok Bahang & Kubang Semang), Perak (black water stream near Bukit Merah lake and Taiping Lake Garden) and Selangor (stream from Klang Gates dam). However, it is likely to be more widespread (Chew and Siti-Munirah, 2010). Ecology. In its native habitat, it grows in tropical climates with a brief dry season, in shallow (up to 3 m deep), warm (18–30oC), acidic to slightly acidic (pH 4–7), more-or-less stagnant water in lakes, streams and floodplains. It is a light-demanding plant. It thrives on organic nutrients when it becomes fast growing (e.g., its stem can grow 12 cm a month). It propagates from plant fragments as well as from seed. It is therefore pre-adapted to conditions in Peninsular Malaysia. Specimens examined. Johor, Kota Tinggi, Sg. Sedili Kechil, Imin et al. FRI 63196 November 2008 (KEP); Pahang, Tasik Chini. Chew et al. FRI 63338 June 2009 (KEP). Uses. Cabomba furcata is an ornamental plant in the aquarium trade. It is cultivated commercially in Malaysia for its pretty reddish, feathery fan-leaves and is readily available for sale in aquarium shops. CONSERVATION IMPLICATIONS The ability of Cabomba species to grow and infest water bodies and the near impossibility of exterminating them led the New South Wales Department of Primary Industries, Australia, to declare Cabomba species (with the exception of C. furcata, which does not grow well there) as noxious weeds (Ensbey 2004). This means that these species ‘must not be sold, propagated or knowingly distributed’. In a study done by Brunel (2009) on aquatic plants imported into Europe, Singapore was listed as the top exporter and Malaysia the fourth. Cabomba aquatic and C. caroliniana were the second and third most imported taxa, totalling more than 1.8 million plants, and the consignments are reported to have often being imported under incorrect or invalid names such as “Cabomba asiatica”. Cabomba furcata is now widespread in both natural and man-made water bodies in Peninsular Malaysia and there is one confirmed locality for C. aquatica (Chew and Siti-Munirah 2010). It is not known when Cabomba species were first introduced into Peninsular Malaysia nor whether they were accidentally or purposely introduced. However, we strongly suspect that the introduction is related to the high demand for export either from Malaysia or Singapore. However, for natural ecosystems their introduction is cause for grave concern because Cabomba has been shown to outcompete native species, reduce water quality, and impede the passage of boats. This has already occurred in Tasik Chini where Rajah and Teoh (2004) reported that a combination of dam building in 1995, organic pollution from sewage effluent 247 from tourist facilities, and run-off from agricultural practices has led to rampant growth of C. furcata, which now impedes the movement of boats and is implicated in the decline of the lotus population, a major tourist attraction for the lake. It has also led to the disappearance of the native Utricularia punctata Wall. ex A.DC., Lentibulariaceae (Chew and Siti-Munirah 2010). It is so extensive in Tasik Chini that its eradication is considered impossible. The populations in the Sg. Sedili area are more restricted in size and so may have been more recently introduced. They could be removed physically before their populations reach infestation levels. Elsewhere, Cabomba is likely to become a problem where it grows in ditches by padi fields, e.g. in the Langkap area or near Sg. Mati, because it will impede water flow and quality for these agricultural areas. It is important to eradicate both these invasive Cabomba species before they become established and to take care that they are not introduced into new areas. ACKNOWLEDGEMETS This research was carried out as part of the Flora of Peninsular Malaysia Project (Project no. 01-0401-0000 Khas) at the Forest Research Institute Malaysia funded by the Ministry of Science, Technology and Innovation (MOSTI). We thank Marian Ørgaard for providing a copy of her Cabomba paper, to Ruth Kiew for helpful comments in improving the manuscript. The first author thanks Wetlands International for the opportunity to carry out botanical collecting at Sedili Kechil and to Imin Kamin for help in the field. REFERENCES Chew, M. Y. and Siti-Munirah, M. Y. 2010. Ecological Implications from the Naturalisation of Noxious Cabomba Waterweeds in <<Malaysia>>. Malaysian Naturalist 63: 19–21. Brunel, S. 2009. Pathway analysis: aquatic plants imported in 10 EPPO countries. Bulletin OEPP/ EPPO 39: 201–213. Ensbey, R. (2004). Cabomba (Agote DPI–330). Australia: New South Wales Dept. Primary Industries. pp. 3. Heywood V. H., Brummit, R. K., Culham, A. and Seberg, O. (2007). 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