Pleione 6(1): 110 - 116. 2012. ISSN: 0973-9467 © East Himalayan Society for Spermatophyte Taxonomy Diversity of Commelinaceae in erstwhile Kamrup District of Assam, India Moitreyee Handique and Purnima Devi Department of Botany, Cotton College, Dighalipukhuri, Guwahati-781001, Assam, India E-mail: [email protected] Revised 04.05.2012; Accepted 30.05.2012 Abstract A recent survey for the members of Commelinaceae in the erstwhile Kamrup District of Assam recorded the occurrence of 14 species (representing four genera) of which four are exotics. The present record of Commelina communis Linnaeus is an addition to the flora of Assam. Key words: Diversity, Commelinaceae, Kamrup, District INTRODUCTION The day–flower family or the spider-wart family Commelinaceae is by far the largest with an estimated 650 species in 40 genera in Commelinales. The APG II system of 2003 recognizes this family and assigns it to Commelinales in the clade Commelinids in the monocots. Some well- known genera like Commelina (day-flowers) and Tradescantia (spider-warts) are belonging to this family. The stems of these plants are generally well developed and often swollen at the nodes. The flowers are ephemeral, lack nectar and offer only pollen as a reward to their pollinators. Most species are bisexual and tend to have specific flowering seasons and also tend to flower at a specific time of the day as well. Flowers are often short–lived, lasting for a day or less. They are ecologically diverse and are found in different habitats. Many species are cultivated for decorative effect as garden ornamentals or house plants and this is their main commercial use. The Commelinaceae of Assam was inadequately studied. Of the recent investigations, mention may be made of Panigrahi (1965), Pathak (1990), Baruah (1992) and Kalita (2008). Study area: A large section of the geographical area of North-East India is hilly and mountainous. Total geographical area of this part of the country is sharing only 8 % i.e. 2,55,037 sq km and of this about 47 % area is forest-covered. The region is referred as ‘eight sisters’ of which Assam is the largest. Kamrup is one of the districts of Assam. Geographically, Kamrup district is surrounded by hills and lies approximately between 25.46o and 26.49o North Latitude and between 90.48o and 91.50o East Longitude. It covers an area of 6882 sq km. The mighty river Brahmaputra flows through it from east to west. Climate is sub-tropical with semi-dry summer and cold winter. Annual rainfall ranges from 1500 mm to 2600 mm. MATERIALS AND METHODS The present study is the outcome of 2 years of critical systematic study of members of Commelinaceae in the district of Kamrup. Field trips were carried out in every season and in all the localities of the area. Visual observation and specimen samples were collected at different reproductive stages to prepare mounted herbarium sheets following Jain & Rao (1977). The Moitreyee Handique & Purnima Devi 111 plants were identified with the help of available literature like Flora of Sikkim (Hajra & Verma 1996), Flora of Maharastra State (Sharma et al 1996), Assam’s Flora (Chowdhury 2005) and also by matching with the correctly annonated materials available in ASSAM herbarium. The specimens collected are all deposited in the herbarium of Cotton College, Guwahati and a set will also be deposited in the herbarium of Gauhati University, Guwahati. RESULTS AND DISCUSSION During the field studies in the erstwhile Kamrup District of Assam, as much as 14 species of commelinids were recorded. These are now enumerated below along with their brief descrip- tions, habitat and distribution. Sometimes a note on their uses was also provided. Photographs of the collected species are provided in Plate I. Commelina benghalensis Linnaeus, Sp. Pl. 41. 1753: Hooker f., Fl. Brit. India 6: 370. 1892: Chowdhury, Assam’s Flora. 293.2005. Commelina canescens Vahl, Enum. Pl. 2: 173. 1805. A perennial herb; lamina ovate, 2.5 – 7.5 cm long, 1.5 – 4 cm broad, stems can be erect or crawling on the ground, flowers zygomorphic, chasmogamous flowers staminate and bisexual, subterranean cliestogamous flowers bisexual, petals 3, upper 2 petals blue, with lower petal white or lighter; seeds rectangular, 1.6 – 3 mm long, brown to black. Habitat: Often found in roadsides Flowers & Fruits: June – October Specimen cited: Gandhi Basti, MH 12; dated 14.07.2008 Distribution: Tropical & Sub-Tropical Asia & Africa, China, Provinces of Hebei & Sichuan, islands of Shikoku & Kyushu, Ethiopia. Note: In China, the plant is medicinally used as a diuretic and anti-inflammatory. (Hong & DePhilipps 2000); in Pakistan, it is used as fodder & also eaten by human as a vegetable. (Qaiser & Jafri 1975); in Nepal, a paste prepared from the plant is used to treat burns (Manandhar & Manandhar 2002). Commelina communis Linnaeus, Sp.Pl. 1: 40. 1753. Commelina barbata Lamarck in Tabl. Encycl. 1: 129. 1791. An annual herb native to East Asia and parts of South East Asia; stems prostrate towards the base but erect upwards. Lamina sessile, lanceolate to ovate; flowers subtented by spathe; petals three; stamens 3 fertile and 3 sterile; ovary ellipsoid, about 2 mm long; capsules glabrous, brown, 2-valved; seeds triangular. Habitat: Found in moist soil Flowers & Fruits: June – October Specimen cited: Rajgarh, MH 26; dated 04.08.2008 Distribution: Asia, China, Taiwan, Japan, Korea, Russian Far East, Cambodia. Note: In China, it is used as a medicinal herb for treating sore throat and tonsillitis (Hong & DePhilipps 2000). In Japan, it is grown for its petals which yield a blue juice used in manufacturing a type of paper (Ohwi 1965). Commelina suffruticosa Blume, Enum. Pl. Jan. 1: 3. 1827; Chowdhury, Assam’s Flora 293. 2005; Hooker f., Fl. Brit. India. 6: 374. 1892. Commelina rugulosa C.B. Clarke in J. Linn. Soc., Bot. 11: 446. 1871. A perennial herb with erect stems. Lamina ovate–lanceolate, 8 – 13 cm long; flowers white; capsules subglobose, laterally flattened, 3.8 – 5 mm long, 2-valved; seed 1 in each locule, light brown. Habitat: Found in the moist soil of hilly areas Flowers & Fruits: August – October Specimen cited: Kamakhya hills, MH 46; dated 29.08.2008 Distribution: Himalayas, Nepal, India, China, Japan, Malaysia. 112 Commelinaceae in Kamrup District of Assam PLATE – I. Fig. 1. Commelina benghalensis; Fig. 2. Commelina communis; Fig. 3. Commelina suffruticosa; Fig. 4. Commelina paludosa; Fig. 5. Commelina diffusa; Fig. 6. Cyanotis cristata; Fig. 7. Floscopa scandens; Fig. 8. Murdannia spirata; Fig. 9. Murdannia japonica; Fig. 10. Murdannia nudiflora; Fig. 11. Tradescantia pallid; Fig. 12. Tradescantia spathacea; Fig. 13. Tradescantia sillamontana; Fig. 14. Tradescantia zebrina Moitreyee Handique & Purnima Devi 113 Commelina paludosa Blume, Enum. Pl. Javae. 1: 2. 1827; Hooker f., Fl. Brit. India 6: 372. 1892. Commelina oblique Buchanon-Hamilton ex D. Don, Prodr. Fl. Nepal. 45. 1825, non Vahl 1806 nom. illegit.; Chowdhury, Assam’s Flora. 293. 2005. A perennial herb, stems generally diffuse, often erect; leaves sessile; lamina lanceolate – ovate, 5 – 8 cm long, spathes 2 – 3.5 cm long, folded, 1.5 – 2 cm broad, obliquely funnel shaped; petals blue; capsules ovoid–globose, 3-valved; seeds dark brown, 1 per valve. Habitat: Found in moist places Flowers & Fruits: August – November Specimen cited: Kamakhya hills, MH 54; dated 29.08.2008 Distribution: Pakistan, India, Sri Lanka, Bangladesh, Indonesia, Malaysia, Philippines. Note: In Bangladesh, people of Chakma tribal community, residents of Hatimara (south) village of Rangamati district, uses the leaf extract orally 2 – 3 times a day to treat dysentery (Rahmatullah et al 2011). Commelina diffusa Burman f., Fl.India. 18, t. 7, f. 2. 1768; Chowdhury, Assam’s Flora 293. 2005; C. nudiflora sensu Hooker f., Fl. Brit. India 6: 369. 1892 non L. 1753. Annual herb, creeps along the ground, branches profusely. Lamina lanceolate to ovate, 3 – 12 cm long, spathes solitary, bright green; petals blue; capsules oblong, trigonous, 3-valved, seeds 1 per valve, deeply reticulate, brown, 2 – 2.8 mm x 1.4 – 1.8mm. Habitat: Found along roadside ditches, waste places Flowers & Fruits: May – November Specimen cited: Chandrapur; MH 62; dated 25.09.2008 Distribution: China, Provinces of Gyuandong, Guangxi, Guizho, Japan, West Indies, Virgin Islands, Hawaii. Note: In China, it is used as febrifuge & diuretic. A dye is also obtained from the juice of corolla for use in painting (Hong & DePhilipps 2000). Cyanotis cristata (Linnaeus) D. Don, Prodr. Fl. Nepal. 46. 1825; Hooker f., Fl. Brit. India 6: 385. 1892; Chowdhury, Assam’s Flora 293.2005; Commelina cristata Linnaeus, Sp. Pl.1: 42. 1753. An annual prostrate herb, native to Asia, with erect ascending branches, lamina ovate to oblong, 5 – 10 cm x 1–1.5 cm, sessile, flowers blue in terminal clusters subtended by folded spathes, capsules 3 – 4 mm long, obtuse, membranous, usually 6 seeded; seeds 1–2 mm long. Habitat: Often found in the wet spots, especially on hills Flowers & Fruits: July – September Specimen cited: Nabagraha hills, MH 65; dated: 30.09.2008 Distribution: Most of Tropical Asia and Africa, especially on the hills. Note: The root has medicinal value and can be used for the relief of swelling and snakebite (Hong & DePhilipps 2000). Floscopa scandens Loureiro, Fl. Cochinch. 193. 1790; Hooker f., Fl. Brit. India 6: 390. 1892; Chowdhury, Assam’s Flora 293. 2005; Aneilema hispida D. Don, Prodr. Fl. Nepal: 45. 1825. A trailing perennial herb with fleshy, erect stem; lamina lanceolate to linear–lanceolate; flowers pink in large hairy panicle stamens 6, filaments 4 – 5 mm long, anthers yellow, ovary stipitate; capsules ovoid, compressed; seeds gray-blue. Habitat: Found in roadside ditches Flowers & Fruits: July – November Specimen cited: Amingaon, MH 73; dated: 13.10.2008 Distribution: Bhutan, India, Laos, Myanmar, Sikkim, Thailand, Vietnam, Oceania.