Piper arnottianum (Miq.) C. DC. Prodr.

Mukherjee, Prasanta Kumar, 2018, Nomenclatural notes on Piper Linn. (Piperaceae) from India II, Phytotaxa 338 (1), pp. 17-32 : 19

3. Piper arnottianum (Miq.) C. DC. Prodr. 16(1): 352. 1869

Basionym:— Chavica arnottiana Miq. Syst. Piperac. 1: 268. 1843. pro parte excl. syntypus Piper chuvya Hunter nom . nud. Hb. Finlays. Wallich 6651A.

Type:— INDIA: Kerala, Piper siriboa Herb. Madr. ex Itiner. Travanc. in Wallich 6651 B (lectotype designated here U1476682 image!– right hand specimen; isolectotypes K001124418 image!, GZU 00256189 image!, CAL!–right hand specimen only) .

Piper hapnium Buch. -Ham. ex Hook. f. Fl. Brit. India 5: 86.1886 pro. parte excl. syntype BANGLADESH: Phuranbari, Hamilton 101 in Wallich 6650D, syn. nov.

Distribution:— INDIA: Tamilnadu, Kerala, Northern Division (?). BANGLADESH, THAILAND ( SIAM!).

Note:— F.A.W. Miquel (1843) described Chavica arnottiana Miq. based on (i) Piper chuvya Hunter Hb. Finlays. in Wallich 6651A and (ii) Piper siriboa Herb. Madr. ex Itiner. Travanc. Wallich 6651 B. A sheet at U (1476682) bearing the annotation as Chavica arnottiana by Miquel has two specimens. Wallich 6651A on the left has two leaves which are different from that in 6651B on the right. Wallich 6651B matches exactly Miquel’s description and illustration (1845. t.40). Sheets of Wallich 6651A and 6651B are also present at K (001124417 & 001124418 respectively) but specimens on them differ from each other. J. D. Hooker (1886) noted that Wallich 6651A is different from Wallich 6651B, being a Siam plant, having glabrous leaves and “is in too imperfect state for determination”. However, the image of Wallich 6651A on the web portal of K shows that it is in good condition. The leaves are elliptic with an acute base. The peduncle of the female spikes is shorter than the spike and the fruits are densely packed on a thick rachis. At CAL, a sheet 3792400 has two different specimens with both the labels together. The left hand specimen, supposedly representing Wallich 6651A, is identifiable as Piper retrofractum Vahl (1804: 314) and is different from the other in the upper, right-hand region. Wallich 6651B at GZU has leaves and other fragmented parts similar to Wallich 6651B at U, K, and CAL. The identity of Wallich 6651A is left unresolved following Hooker (1886). It bears to recall that Wallich’s specimens at different herbaria are notoriously mixed up and vary considerably.

Casimir de Candolle (1869) needlessly cited additional materials, Wallich 6650 E & F, while transferring C. arnottiana to Piper . Wallich 6650F at K (001124414) has been identified by Hooker (in pencil) as P. chaba Hunter (= P. retrofractum Vahl (1804: 314) .This is mounted along with Wallich 6650D (K001124413). Wallich 6650E at CAL has two plants; the left hand one is P. retrofractum Vahl and the right hand one is Piper silletianum P. K. Mukh. (2016: 188) .

Matters relating to Piper hapnium , a replacement name for P. arnottianum proposed by Hooker (1886: 86), have already been discussed while dealing with P. anisotis Hook. f. Wallich 6651B at U (1476682), annotated by Miquel as Chavica arnottiana ( P. arnottianum ), is designated here as the lectotype since the material is complete with leaves and a female spike matching the original description. Similar specimens at K (001124418), GZU (000256189) and CAL (379240, right hand specimen only) are isolectotypes.