Piper hymenophyllum

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Piper hymenophyllum


Scandent or creeping shrub, climbing branches rooting at nodes. Stem ridged, pubescent with recurved hairs. Petiole 0.5-1 cm long, pubescent, vaginate to apex; blade not conspicuously glandular-dotted, elliptic, subobovate or ovate, 4-17 x 3-6.5 cm, (on young creeping branches ca. 1.5-5 x 0.8-1.8 cm), margin occasionally ciliate, apex (long-)acuminate, base unequally attached to petiole difference 0.1-0.7 cm, unequally cordate or obtuse, glabrescent but veins may be recurved-pubescent; pinnately veined, secondary veins 6-8 per side, originating from throughout primary vein, impressed above, prominent below, tertiary veins inconspicuously reticulate. Inflorescence horizontally oriented? later recurved; peduncle 0.8-2 cm long, pubescent or glabrescent; spike protandrous (presenting staminate flowers first, pistillate flowers afterwards), 1-3.5 cm long, green, not apiculate; floral bracts pubescent at base, densely marginally fringed; stamen 1 per flower, far exserted, recurved, 2-3 mm long. Fruits obovoid to depressed globose, glabrous, stigmas 3 or 2, recurved, 0.5-1 mm long.


Guianas present, Southern America
The Guianas and Brazil; 34 collections studied (GU: 4; SU: 16; FG: 14).


This creeping species is easily recognized by the difference in flowering pattern. At first sight the species seems to be dioecious, but actually it is protandrous. The flowers are unique in the Guianan species in having only one stamen. The stamen has long filament that elongates before the ovary develops.
There is a great variety in leaf measurements, which may result in incorrect identification of immature collections.
When Wight used the name Piper hymenophyllum, illustrating his own specimen from India, he did not realize that this specimen did not belong to Miquel's species. Despite this, his new combination applies to the basionym, Artanthe hymenophylla.
De Candolle in transferring Nematanthera guianensis to Piper nematanthera cited two collections: Hostmann 19 (which is an error, because the number 10 is clearly written on the Kew voucher) and Kappler 1438. Miquel only mentioned the Kappler specimen which thus is the type of Nematanthera guianensis.
Trelease and Yuncker reduced Piper sagotii to variety sagotii under P. nematanthera. They indicated that additional material might show intermediate leaf shapes and measures. In Jonker & Jonker-Verhoef 418 there is a young, creeping branch bearing leaves of ca. 1.7 x 0.8 cm, the size of leaves in var. sagotii, whereas the leaves on the other branches are up to 17 x 6 cm, the size as described for the typical variety. To conclude, there is no reason to maintain var. sagotii.