THREE NEW RECORDS OF LAURACEAE FOR BANGLADESH

During the floristic explorations conducted in 2022–2023 in different forest areas of the northeast region of Bangladesh, some specimens of the family Lauraceae were collected. The critical examinations of these specimens have revealed that they belong to the species Litsea kurzii , Litsea stocksii , and Litsea variabilis of the family Lauraceae. These species are new to the flora of Bangladesh. A detailed taxonomic description, including data on ecology, distribution, and use, a list of representative specimens examined, and photographs of each of these species have been provided.


Introduction
Taxonomists are relentlessly describing new extant species every year. In Bangladesh, the endeavour of exploring new plant species is continuing, and as a consequence, the taxonomists of this country have published a notable number of new records in the last few decades, though sporadically. Likewise, after the publication of the Encyclopedia of the Flora and Fauna of Bangladesh (EFFB) (Ahmed et al. 2008(Ahmed et al. -2009(Ahmed et al. , 2009Siddiqui et al. 2007), around 281 new records of Angiosperms have been published, mostly with information on the specific distribution of the recorded taxa (Rahman and Hassan, 2017;Islam and Rahman, 2017;Sourav et al., 2017;Ara and Hassan, 2018;Rahman and Uddin, 2018;Uddin, 2018;Alfasane et al., 2019Alfasane et al., , 2020Hossain et al., 2020;Sultana and Rahman, 2021;Hossain et al., 2022;Rahman et al., 2022;Sultana et al., 2022;Uddin and Uddin, 2022). It means that in the last 13 years, around 7.78% of the EFFB's record of 3611 species and 5.6% of Khan (1977)'s estimate of 5000 species of Angiosperms to exist within the territory of Bangladesh have been newly added to the flora of this country. As a result, the total number of Angiosperm species in Bangladesh has increased to 3892 through the addition of these additional records to the 3611 species listed in the EFFB. Now, if Khan's (1977) estimation of 5000 species to occur in Bangladesh is considered, the existence of around 1108 (22.16%) species and their status in this country is yet to be confirmed through intensive and extensive field explorations, and the plant taxonomists of this country are working towards this goal.
Recently, in 2022-2023, floristic surveys were conducted in the northeast region of Bangladesh. During these surveys, some specimens of angiosperms collected by the authors from the Lithitila forest area of Juri, Moulvibazar district, and Nijpat of the Jaintiapur hill areas of Sylhet district appeared to be different. These specimens were preliminarily identified as belonging to Lauraceae, but they did not match with any specimens of this family collected previously from this country or with the taxonomic description or key characters of any species of this family known or reported previously from Bangladesh. Following the rigorous examinations of these specimens, matching their characters with the relevant published descriptions, key characters, and specimens available at the local herbaria and the Herbarium of the Botanical Survey of India (CAL), and images of Lauraceae voucher specimens available on the websites of a few international herbaria (e.g., Kew Herbarium, K and Missouri Botanical Garden's Herbarium, MO), these unknown specimens were found to belong to three species of the genus Litsea Lam. of the Lauraceae. These species have never been mentioned or reported previously in any publication on the flora covering the present territory of Bangladesh. Hence, these three species have been confirmed as new to the flora of Bangladesh. The specimens are presently deposited at the Bangladesh National Herbarium (DACB) and the Jahangirnagar University Herbarium (JUH).

Materials and methods
Field surveys were conducted from December 2022 to May 2023 in the evergreen, semievergreen, and deciduous forests in the northeast region of Bangladesh that belong to the administrative boundaries of the Habiganj, Moulvibazar, and Sylhet districts of Sylhet division. These field surveys were carried out in all three major seasons of the year, mostly in the forests and scrub jungles of the hilly regions and foothills of Habiganj, Moulvibazar, and Sylhet districts. The freshly collected plant specimens were processed, dried, and preserved following standard herbarium techniques (Hyland, 1972;Jain and Raw, 1977).
The taxonomic identification of these specimens was confirmed by matching their characters with the relevant taxonomic literature (e.g., Devis and Cullen, 1965;Geesink et al., 1981;Hooker, 1890;Prain, 1903;Mia, 2009;Li et al., 2008;Ngernsaengsaruay et al., 2011), voucher specimens housed at DACB and JUH, and clear images available on the websites of a few international herbaria (e.g., K, Muséum National d'Histoire Naturelle P, and MO). A taxonomic description of each species was prepared through careful observation and examination of the morphological characters of the representative specimens. Nomenclatural information was verified following recent taxonomic publications (Li et al., 2008) and the nomenclatural databases of POWO (2023), WFO (2023), GBIF Secretariat (2023), and Tropicos (2023). The voucher specimens have been deposited at DACB and JUH.

Results and Discussion
The taxonomic identification of the specimens of Litsea collected from different forest areas of the Sylhet division of Bangladesh has been confirmed as L. kurzii King ex Hook.f., L. stocksii (Meisn.) Hook.f., and L. variabilis Hemsl. The following taxonomic descriptions of these species, including the key for their identification, have been produced based on the collected specimens and field notes recorded during field visits.
Ecology: Often by streams in the rain forest, dry evergreen forests. Distribution: Native to Bangladesh, India (Andaman Is. and Nicobar Is.), Myanmar, and Thailand.
Use: The trunks of the plant are used for making house pillars by the local people. L. kurzii King ex Hook.f. seems similar to L. grandis (Nees) Hook.f., from which it can be easily distinguished by its tomentose chartaceous leaves, densely reddish-brown pubescent petioles, pale-green to yellowish and pubescence bracts, perianth tubes of ca. 0.4 cm in diam, 0.3-0.5 cm long fruiting pedicel, and 0.5-0.6 cm long infructescence stalks, in contrast to the sparsely pubescent coriaceous leaf, puberulous petioles, reddish-brown and puberulous bracts, perianth tubes of ca. 1.1 cm in diam., 0.5-1 cm long fruiting pedicel, and 0.8-1.4 cm long infructescence stalk of L. grandis. ( Fig. 2) Tree, up to 18 m tall, petioles 2.0-2.5 cm long, leaves alternate, leaf blades oblong to lanceolate, apically acute, 8-20 by 3-6 cm, white glaucous beneath, glabrous, lateral nerves 8-13 pairs. Inflorescence umbel, monoecious, 2.5 cm long, greyish tomentose, male inflorescence 4-8 flowered and female inflorescence 4-5 flowered, arranged in 1 whorl; pedicels 1 cm long in male flower, 0.5 cm long female flower; In male flower stamens 8-10, introrse, unequal, 6 larger, different in length, 4 smaller, largest one c. 0.34 cm long, filament c. 0.24 cm long, sparsely hairy, anther c. 0.12 cm long. Ovary in female flower straight, 1.0-1.3 mm by 0.6-0.8 mm half inferior, covered with the hairy perianth; styles 0.2-0.3 mm long; stigma dilated, 0.2-0.3 mm by 0.2 mm. Fruiting peduncles 1-2 cm long at the young stage; pedicels up to 0.5 cm long; perianth tube 0.5-0.7 cm long, up to 0.2 cm in diam. at the distal part of the fruit. Berry oblong, 1.0-1.5 cm long, seated on cup-like perianth tube; young fruit almost completely inserted into perianth tube; half portion of fruit inserted into perianth tube at maturity. Flowering and fruiting period: May to January.
Ecology: In evergreen and semi-evergreen forests. Distribution: Native to Bangladesh and India.

Litsea variabilis
Ecology: In the moist evergreen forest beside the canal. Distribution: Native to Bangladesh, China, Laos, Thailand, and Vietnam. Uses: The wood is heavy, slightly hard, and resistant to water and borer insects. It is used for furniture-making and house construction.
L. variabilis Hemsl. seems closer to L. khasyana Meisn, from which it can be clearly distinguished by its pubescent petioles and globose fruits, in contrast to L. khasyana's glabrous petiole and ellipsoid or cylindrical fruit.
The images of all three species presented have been collected from mature plants naturally growing in the study area. The finding of these three species will make little contribution to the efforts to confirm the existence of more species in Bangladesh in addition to the current record of 3892 angiosperm species for this country.