THREE NEW RECORDS OF AROIDS (ARACEAE) FOR BANGLADESH

Three aroid species, namely Colocasia gigantea (Blume) Hook. f., Epipremnum pinnatum (L.) Engl. and Scindapsus perakensis Hook. f. under the family Araceae are recorded for the first time for Bangladesh. An updated nomenclature including important synonyms, illustrated descriptions, flowering and fruiting times, specimens examined, ecology, geographical distribution, occurrance within Bangladesh and uses for each species have also been provided. Introduction Araceae is a family of about 110 genera and 2500 species (Croat 1979) distributed mostly in the tropics and subtropics of both the hemispheres. Recent publications indicate that about 65 species of the family Araceae have so far been identified in Bangladesh (Ara 2001, Ara and Hassan 2005 a,b, Ara et al. 2004, 2005 a,b). The list, probably, is not yet complete. Field collections from Rangamati, Khagrachari, Bandarban, Sylhet and Maulvi Bazar districts indicate that three species of the family, namely Colocasia gigantea (Blume) Hook. f., Epipremnum pinnatum (L.) Engl. and Scindapsus perakensis Hook. f. were not reported from the territory of Bangladesh by many previous workers, for example, Hooker (1893), Prain (1903), Heinig (1925), Calder et al. (1926), Sinclair (1955), Rao and Verma (1976), Huq and Khan (1984), Nicolson (1987), Karthikeyan et al. (1989), Khan et al. (1994), Noltie (1994), Mia and Khan (1995), Rahman and Uddin (1997), Uddin et al. (1998), Uddin and Rahman (1999), Rashid et al. (2000), Ara (2001), Khan and Huq (2001) and Rahman (2004a, 2004b). The genus Epipremnum Schott has not been reported previously from Bangladesh. So, it is a new generic record for the country. Materials and Methods The plant materials have been collected from different forest areas of Bandarban, Khagrachari, Maulvi Bazar, Rangamati and Sylhet districts during several field trips between 1998 and 2004. The specimens, after study, have been preserved in the Bangladesh National Herbarium (DACB). The published articles of Engler and Krause (1908, 1920), Li Heng (1979), Nicolson (1979, 1987), Karthikeyan (1989), Hay (1996) and Boyce (1998) on the family Araceae helped the authors to identify the three newly recorded species. Corresponding author. Department of Botany, University of Dhaka, Dhaka-1000, Bangladesh.


Materials and Methods
The plant materials have been collected from different forest areas of Bandarban, Khagrachari, Maulvi Bazar, Rangamati and Sylhet districts during several field trips between 1998 and 2004.The specimens, after study, have been preserved in the Bangladesh National Herbarium (DACB).The published articles of Engler andKrause (1908, 1920), Li Heng (1979), Nicolson (1979Nicolson ( , 1987)), Karthikeyan (1989), Hay (1996) and Boyce (1998) on the family Araceae helped the authors to identify the three newly recorded species.
In this communication, detailed taxonomic description, correct names with important synonyms, specimen citation, notes on ecology, geographical distribution within and outside the country, economic importance and illustration of each species have been presented based on the fresh specimens.All the specimens examined including the types have been cited.
Note: Colocasia gigantea can easily be distinguished from all other Colocasia species so far reported from Bangladesh (Ara and Hassan 2005a,b) by the presence of the following characters together: petiole pruinose, leaves very large, ovate-cordate, spathe 12-24 cm long, limb oblong or elliptic-oblong, cymbiform, cuspidate and very short appendage of the spadix.
Uses: The petiole of the plant is used as one of the ingredients of "Salad".Its leaves and petioles are used in making delicious curry.The petioles and leaves of the plant contain iron, calcium and vitamin-C.In Bangladesh, children and women generally suffer from the deficiency of iron, calcium and vitamin-C and, as such, the plant may be consumed by the common people to suppliment as a source of these minerals or vitamin.The plant should be cultivated in kitchen garden of each family for its ready availability.It can also be cultivated on a commercial basis for meeting the demand of domestic consumption as well as for exporting to different countries that will bring foreign exchange for the country.Large, root-climber to 15m.Pre-adult plant usually forming modest terrestrial colony.Adult plant with stem 2.5-4 cm diam., internodes 2-25 cm long, branched.Petiole 19.5-60 cm × 3-13 mm, smooth, dark-green, pulvinate at both ends, sheath running to upper pulvinus and soon disintegrating to leave a reticulate network of intertwined venation.Leaf blade subleathery, oblong, base wide cordate, 10-93 × 5-60 cm, regularly pinnatifid to (rarely) entire, ovate to oblong-elliptic in outline, apex acute to acuminate, base rounded to slightly cordate, divisions pinnatifid to pinnatisect, pinnae 1.2-6.5 cm wide, 12-13 per side, narrowly lanceolate to somewhat falcate, with 1-3 equally strong, parallel costae, apex truncate to acute, the terminal one usually subrhomboid, dark-green above, paler beneath.Peduncle 5.5-21.5 × 0.4-1.0cm, stout, terete, pale-green, enveloped by sheath, finally withering.Spathe canoe-shaped, 7-18 × 3-10 cm, green outside, yellow inside, apex acuminate.Spadix bisexual, 8.5-19.5 × 1.1-3.5 cm, sessile, cylindrical, bluntly tapering towards the apex, base slightly obliquely inserted, green.Flowers 3-7 mm diam., ovary 4-12 × 2-7 mm, cylindrical, basal part slightly compressed; ovules 2 or 3; stylar region 3-7 × 1.5-4 mm, trapezoid, apex flattened; stigma linear, 2-6 × 0.1-0.5 mm, longitudinal; stamens 4; filaments 5 × 1 mm; anthers narrowly ellipsoid, 1.5-2 × 0.75-1 mm.Fruit green.Seeds reniform, smooth, 4.5 × 3.5 mm, pale to brown.Flowering and fruiting time: April to May.Ecology: Creeping on trees or on stone walls in shady and moist conditions in the tropical rain forests or deciduous forests.

Epipremnum pinnatum
Geographical distribution: Southeastern Asia through Malesia to Oceania.

Note:
The species is recognized by its high-climbing habit; sheath soon withering, but leaving a mat of intertwined venation; blade pinnatisect (adult) to entire (juvenile), to 1 x 0.5 m., often with tiny perforations along midrib; spathe creamy, soon withering; spadix sessile, to 17 x 3 cm.
Note: Earlier three species of Scindapsus, namely S. officinalis (Roxb.)Schott, S. pictus Hassk., and S. scortechinii Hook.f. have been reported within the Bangladesh territory by Ara (2001) and Ara et al. (2004).Scindapsus perakensis differs from the above-mentioned three species in its oblong-lanceolate or falcately lanceolate, acuminate, thinly coriaceous leaves with acute or rounded base, 21-30 cm long; in broad petioles, 10-15 cm long; in 8-10 cm long peduncle, very stout and in spadix longer than spathe.Use: The plant, as a climber on wall or on big tree, possesses ornamental value for its showy oblong-lanceolate leaves borne on sheathing petioles.
Thanks are also extended to Mrs. Mahmuda Akhter, Artist, Bangladesh National Herbarium, for helping the authors in preparing the line drawings of the specimens.