SYSTEMATIC STUDIES OF THE GENUS ASPARAGUS TOURN. EX LINN. (LILIACEAE) IN BANGLADESH

The genus Asparagus Tourn. ex Linn. represented by five species in Bangladesh, viz., Asparagus adscendens Roxb., A. densiflorus (Kunth) J.P. Jessop, A. officinalis L., A. racemosus Willd. and A. setaceus (Kunth) J.P. Jessop is revised. Each species is described with updated nomenclature, important synonyms, phenology, specimens examined, chromosome number, habitat, distribution, economic value and mode of propagation. A dichotomous bracketed key to the species and illustrations along with photographs of four species are provided.

. Ecologically, Asparagus species are tolerant to drought and high temperatures growing under forest cover as well as in open habitats including predesertic steppes. They constitute a lianascent layer characterizing the Mediterranean forests along with species of other genera, i.e. Smilax L. and Ruscus L. (Schnitzler and Arnold, 2010). These lianas play a key role in the ecology and dynamic of forests and may be helpful as indicators for the monitoring and management of forest ecosystems (Naidu et al., 2014).
In Bangladesh, Asparagus appears to be the second largest genus in the family Liliaceae, represented by five species including both wild and cultivated ones. Hooker (1892) recognized 17 Asparagus species from the Indian sub-continent, of which only three species were reported from the territory of present Bangladesh. Afterward, Prain (1903) listed two Asparagus species from the area of current Bangladesh. Hassan (2007), and Afroz and Hassan (2008) documented four species of Asparagus occurring in Bangladesh with inadequate taxonomic description. In the recent past, Akter et al. (2017) studied the fluorescent banding in A. racemosus, A. officinalis and A. setaceus in Bangladesh with differential banding patterns. Despite a few studies on Asparagus were conducted earlier based on its morphology and cytology, however, there has been no detailed taxonomic study on this medicinally and ecologically important genus in Bangladesh. Therefore, the present study aims to revise the genus Asparagus in Bangladesh for the first time.

Materials and Methods
Plant samples of different Asparagus species were collected from different parts of the country and planted in the Dhaka University Botanical Garden for further study. The collected plant specimens were critically studied and examined, and were supplemented by the specimens housed at the Dhaka University Salar Khan Herbarium (DUSH) and Bangladesh National Herbarium (DACB). Identification of the Asparagus species were confirmed in consultation with standard literature (Hooker, 1892;Deb, 1983;Karthikeyan et al., 1989;Noltie, 1994;Raven and Zhengyi, 2000;Utech, 2002;Hassan, 2007) and matching with authentically identified herbarium specimens deposited at DUSH and DACB. Each species is described with updated nomenclature, important synonyms, English and Bangla names, flowering and fruiting period, specimens examined, chromosome number, habitat, distribution, economic value, and mode of propagation. The updated nomenclature has been determined using The Plant List (2013), and The Plants of the World Online (POWO, 2022). A dichotomous bracketed key to the species and illustrations with photographs of four species are also provided. The voucher specimens are deposited at DUSH.
Habitat: Sal forests and well-drained moist soils in semi-shady condition. Distribution: Afghanistan, Argentina, Bhutan, India, Iran and Pakistan (GBIF, 2020). Economic value: Tuberous root is a source of nutritious starch. The roots are demulcent, diaphoretic, galactogogue and stimulant, and are useful in the treatment of diarrhoea, dysentery and general debility (Hassan, 2007).
Economic value: An infusion of the leaves is used to treat thrush and ulcers in the mouth, for abdominal pains, as a tonic to boost immunity, as a cleansing agent to rid the body of "poison" and "dirty blood" (Mfengwana and Mashele, 2019).

Asparagus officinalis
Habitat: Fields, fence rows and roadsides. The species is cultivated since ancient Greek times. Economic value: Tuberous roots are used as aphrodisiac, alterative, tonic, demulcent and diuretic. Ethanol extracts of aerial parts possess anticancer properties (Ghani, 2003). The plant is ground with other ingredients, made into pills, and fed to cattle for diarrhoea (Alam, 2000). Tubers are used as a vegetable (Deb, 1983). Root is used as antidepressant, anti-diarrhoeal, antibacterial, analgesic, anti-inflammatory and antioxidant (Hasan et al., 2016). The species can improve the milk production and reproduction capacity of dairy animals (Kushwah et al., 2018).
Ethnobotanical information: Tuberous root paste mixed with sesame oil or coconut oil is used as a hair tonic. Root taken with milk is useful in gonorrhoea (Hassan, 2007).
Economic value: Aaparagus setaceus is used as a popular ornamental plant because of its attractive characters of extremely feathery, soft leaves, and an elegant posture (Li et al., 2020). This species is reported to have multiple uses in traditional oriental medicine (McGaw and Eloff, 2008).
Ethnobotanical information: Foliage is used for decorative purposes by florists (Hassan, 2007).