Piper caninum Blume

Gardner, R. O., 2013, Piper (Piperaceae) in New Guinea: the climbing species, Blumea 57 (3), pp. 275-294 : 280-283

5. Piper caninum Blume — Fig. 3a

Piper caninum Blume (1826) 214; Quisumb. (1930) 120; Chew (1972) 5; R.O. Gardner (2006) 580; Spokes (2007) 239; R.O. Gardner (2010) 8. — Type: Blume s.n. (holo L n.v.), Java.

Distribution — Western Malesia to the Solomon Is. and northeastern Australia.

Habitat & Ecology — In forest, 0– 500(–1600) m altitude.

Notes — Recognized by its chartaceous, greyish to olive-brown leaves which usually have a light cover of short pale bristly hairs. Rarely, the indument is subvillous (Streimann 8368, Morobe Province, near Lae , 250 m). Because of the similarity of leaf shape, texture, glandularity and nervation in P. caninum and P. interruptum , and because of the variability of the latter’s indument, sterile specimens can be hard to place as one rather than the other of these two species.

The two highest-altitude specimens I have seen are both from 1600 m: Brass 24814, Milne Bay Province, Goodenough I.; NGF 37258, Western Highlands, Kopiango .

Van Royen (1982: 1269, f. 403) incorrectly described P. caninum as reaching “the upper subalpine shrubberies [at] 3290 m ”. This altitude, and his f. 403, are based just on Vink 17365, which belongs to P. rodatzii of the P. macropiper species-complex.

Johns et al. (2006: 401) cite a Kloss specimen collected from “Camp IX– XIII” [c. 1700 – 3150 m] on Mt Jaya (Carstenz). I have not been able to check this specimen at BM, and regard even 1700 m as an anomalously high altitude .

The leaf blades of Hoogland & Craven 10805 (East Sepik Province, Hunstein River, c. 150 m) measure only 7 by 2 cm. With this exception, and even at altitudes above 500 m, narrow-leaved plants seem not to occur in New Guinea. This contrasts greatly with the situation in the Philippines ( Gardner 2006).

Three collections have leaves that are unusually coriaceous and glossy: Brass 24814 (cited above); Clemens 4520, Morobe Province, Ogeramnang; NGF 20253, Central Province, Woitape. They are not otherwise unusual.

Takeuchi 14166 (Morobe District, Guam River, c. 80 m, A) has a 30 cm long infructescence (in typical P. caninum , 8(–12) cm) and elongate bracts, as in P. interrruptum . But the densely hairy leaves suggest P. caninum , as do the hairy rachis and stipitate fruitlets. I therefore leave this collection undetermined.

Figures

Fig. 3 Specimens of Piper species. – a. P. caninum Blume. – b. P. decumanum L. – c. P. insectifugum Seem. – d. P. lessertianum C.DC. (a: NGF 26031, A; b: Darbyshire & Hoogland 8124, A; c: Brass 23997, A; d: Cuming 1343, BM).