Piper leptostachyum Miq. Syst. Piperac.

Mukherjee, Prasanta Kumar, 2020, Nomenclatural notes on Piper (Piperaceae) from India III, Phytotaxa 441 (3), pp. 263-273 : 267

6. Piper leptostachyum Miq. Syst. Piperac. 315. 1844

Type:— MYANMAR: Nedaun , river Aatran, Wallich num. list no. 6649 (lectotype designated here) K ( K001124408 ) ; isolectotypes G-DC (G00206817 image!, U (U1476711 &U1476712 image!),

Homotypic synonym:— Piper indicum C. DC. Prodr. 16: 362. 1869. non Garsault Fig. Pl. Med. 3: t. 459. 1764. nom. invalid opus utique oppresum.

Note:— Miquel gave no locality but cited two specimens, Wallich num. list nos. 1540 and 6649, while describing the species. Such specimens could be located at three places. The label on a sheet at U having two barcode numbers (U1476711 & (U1476712) shows no. 1540 only. At K the specimen ( K 001124408) bearing Wallich’s annotation as P. leptostachyum has the label with both the Wallich Num. list nos. 1540 and 6649. The G-DC specimen (G0020817) for Wallich Num. list no. 6649 was annotated as P. leptostachyum by Wallich and as Piper indicum by C.de Candolle. The facts show that Hooker (1886: 95) was wrong to conclude that “Miquel’s citation of Wall. Cat. for this is an error.” Neither Miquel had designated a holotype, nor any of the specimens cited above bears annotation by Miquel. Mention of K ( K 00124408) as the holotype by Suwanphakdee et al. (2016) is an error (Art. 9.1, Turland et al. 2018). So too by Mukherjee (2018) who had unnecessarily mentioned the specimen at G-DC (G00206817) as the holotype. The best option should be to designate a lectotype (Art. 9.2, 9.11 & 9.12, Turland et al. 2018). The specimen at K ( K 001124408) is designated here as the lectotype. This specimen is in best condition in preservation and labeling. The G-DC specimen is stored as P. indicum . The specimen at U lacks Wallich’s 6649 number. Its locality is mentioned as “Nedaun, river Aatran”.

Suwanphakdee et al. (2016: 610) treated P. rhytidocarpum C. DC. and P. leptostachyum Miquel as synonymous. P. leptostachyum is characterized by oblique ovate elliptic leaves with unequal rounded base, veins 9, the upper two veins placed above 1/3 the length of the leaf are alternate; female spikes 15 to 20 cm long, with distantly placed fruits. Leaves in P. rhytidocarpum are ovate-orbicular, rounded equal base, female spikes to 30+ cm, fruits more or less closely spaced. Mukherjee (2018: 27) identified P. leptostachyum and P. rhytidocarpum as distinct species and has made observations on their typification. The error in lectotypification of P. rhytidocarpum by Gilbert & Xia (1994: 194) is repeated by Suwanphakdee et al. (2016: 610). There has been a minor error by Mukherjee (2018: 27) which needs correction; Barcode code number for the holotype of P. rhytidocarpum is (G00207056 and not (G00207656).