The plants have alternate, evergreen or deciduous leaves and small inflorescences that are epiphyllous (growing from the leaf surface). During development, the flowers appear separate from the leaves,[further explanation needed], eventually fusing with the leaf midrib.[4] Flowers are small and yellow-green or purple, followed by red or black berries. Plants are dioecious.[5]
Epiphyllous inflorescences
This trait is rather unusual among plants. This atypical floral position upon a leaf is believed to be an adaption to insect pollination. Pollinators which are too large to be supported by the floral pedicels, land on the leaf surface and can pollinate the flowers, which would not be able to support the pollinators on their own.[6]
The family Helwingiaceae does not exist in the
Cronquist classification (1981), which places this genus in the Cornaceae (dogwood family). Helwingia has also previously been placed in the Araliaceae (ginseng family).[8]
^Dickinson, Timothy A.; Sattler, Rolf (1975). "Development of the Epiphyllous Inflorescence of Helwingia japonica (Helwingiaceae)". American Journal of Botany. 62 (9): 962–973. doi:10.2307/2441641. ISSN0002-9122. JSTOR2441641.
^Dickinson, T. A.; Sattler, R. (1974). "Development of the epiphyllous inflorescence of Phyllonoma integerrima (Turcz.) Loes.: implications for comparative morphology*". Botanical Journal of the Linnean Society. 69 (1): 1–13. doi:10.1111/j.1095-8339.1974.tb01609.x. ISSN1095-8339.
HelwingiaceaeArchived 2006-11-01 at the Wayback Machine, Watson, L., and Dallwitz, M.J. 1992 onwards. The families of flowering plants: descriptions, illustrations, identification, and information retrieval. Version: 29 July 2006.