Brachystemma calycinum var. emarginatum Anant Kumar, 2023

Kumar, Anant, 2023, A new variety of Brachystemma calycinum (Caryophyllaceae) from West Bengal, India with notes on its typification, Phytotaxa 598 (3), pp. 259-263 : 260

Brachystemma calycinum var. emarginatum Anant Kumar , var. nov. ( Fig. 1 )

Type: — INDIA. West Bengal, Alipurduar, Buxa Wildlife Sanctuary, Tashigaon to Rovers point, 12 February 2014, Kumar 59917 (holotype CAL!, isotype CAL!) .

Diagnosis: — Brachystemma calycinum var. emarginatum differs from B. calycinum var. calycinum by densely pilose bracts; petals elliptic-oblong to elliptic-lanceolate, emarginate or bifid at apex, about equal to sepals in length; about 3 times as long as broad; stamens equal to staminodes.

Etymology: —The epithet ‘ emarginatum’ refers to emarginate or bifid petals, one of the diagnostic features that differentiate the new variety from proper variety.

Flowering & fruiting times: —January–April.

Habitat: —The new variety grows in shrubs dominated by Maesa indica ( Roxburgh 1824: 230) Sweet (1826: 268) in open places in semi-evergreen hill forests, and on hedge plants and tea plantations.

Distribution: — India in West Bengal (Buxa Wildlife Sanctuary, Alipurduar and Neora Valley National Park, Kalimpong).

Other specimens examined: — Brachystemma calycinum var. emarginatum . INDIA: West Bengal, Neora Valley National Park, Asalay , 27.015517N & 88.759635E, 589.3m, 22.02.2020, Ranjan, Krishna & Kumar 86862 (Paratype, CAL!) .

Brachystemma calycinum var. calycinum . INDIA: Sikkim Terai, Rhishop , Hb. J. And. 14 February 1867, without collector’s name s.n. (CAL!, Acc. no. 41507) ; Assam, Kobo , 01 December 1911, Burkill 35944 (CAL!, Acc. no. 41514) ; Assam, Robong , 1400m, 24 December 1911, Burkill 37353 (CAL!, Acc. no. 41512) ; Manipur, Ukhrul , 6000ft, 10 March 1948, S. K. Mukerjee 2431 (CAL!) ; Mizoram, Vansil , Lushai hills, year of collection not readable, Mann s.n. (CAL!, Acc. no. 41516) .

Note on the type of Brachystemma calycinum : — Don (1825: 216) described the genus Brachystemma and listing one species ( B. calycinum D.Don ) which is therefore the generitype of the genus (see Art. 10.1-Note 1 of ICN). Don (1825), after a detailed description reported “Hab. in Nepalia. Wallich” so referring to a Wallich’s collection. According to Stafleu and Cowan (1988: 38), Don’s Prodromus is based on Wallich’s specimens preserved at BM, CGE, FI, LINN (Smith’s Herbarium), and PR and “perhaps in various other herbaria”. I traced 7 Wallich’s specimens at BM, CAL, E, and K. Wallich (1829 –1849) mentioned two localities (Napalia and Pandua) in his “Numerical List” but Don (1825) described the genus based on specimens collected from Nepal. Hence, only 4 out of 7 specimens found (those collected in Nepal) can be considered as original material for B. calycinum . They are: K000568116 (http://apps. kew.org/herbcat/getImage.do?imageBarcode=K000568116), K000568119 (http://apps.kew.org/herbcat/getImage. do?imageBarcode=K000568119), BM000583343, and E00317572. Hara & Williams (1979: 53) reported “Wall. s.n., ann. 1819” as a type of B. calycinum . According to the Art. 7.11 of ICN (see also Prado et al. 2015) these two authors inadvertently lectotypified Don’s name.

Figures

FIGURE 1. Brachystemma calycinum var. emarginatum. A) Habit, B) Flowering twig, C) Close view of fully open flower.