Botanische Staatssammlung München, Munich, Germany.
Trees or rarely shrubs, lacking latex and extrafloral nectaries. Leaves alternate, often distichous, simple, base usually slightly to distinctly unequal (oblique), margins entire to (spinose-)dentate or crenulate, petiolate, short, eglandular, stipules present but caducous, eglandular, scaly, latex absent, indumentum simple, venation pinnate, brochidodromous. Inflorescences unisexual, dioecious to rarely polygamo-dioecious or monoecious, axillary or on older leafless nodes or cauliflorous, fasciculate-glomerulate or (pistillate) flowers sometimes solitary, sessile; bracts small, inconspicuous. Flowers actinomorphic, pedicellate, with 4-5(-7) imbricate, free to nearly free, often unequal sepals, petals absent. Staminate flowers with 4-12 stamens, filaments free, anthers basifixed, introrse to rarely extrorse, bilocular, opening with longitudinal slits, disc intrastaminal, flat, entire to variously lobed, pollen 3-colporate, tectate, psilate, or lalongate, pistillode minute or absent. Pistillate flowers without staminodes, disc annular or cupulate (rarely absent), ovary hypogynous, syncarpous, with 1-2(-3) locules, usually pubescent, ovules 2 per locule, placentation axile, anatropous, bitegmic (very rarely unitegmic), style short to absent, stigmas 1-2(-3), short thick and flattened, entire or sometimes bifid. Fruits indehiscent, drupaceous, globose to ovoid-ellipsoid, exocarp and mesocarp leathery to fleshy, endocarp crustaceous, usually 1-seeded by abortion (sometimes 2-seeded); seeds ellipsoid to globose, smooth, anatropous, ecarunculate, sarcotesta when present thin, endosperm copious, embryo straight, cotyledons broad. Chromosome number usually 2n = 40.
Notes on delimitation
- The Putranjivaceae were included in the Euphorbiaceae subfamily Phyllanthoideae [now Phyllanthaceae] for a long time, but were recognized as unusual there because of, among others, the presence of glucosinolates, the unusual fruits and different chromosome base numbers.
Distribution in the Neotropics
- The Putranjivaceae are represented by one genus in the Neotropics, occurring in several vegetation types but usually in tropical moist forests: Drypetes Vahl - a pantropical genus with 21 species in the Neotropics.
- In the New World the majority of species are Caribbean.
Distinguishing characters (always present)
- The single genus is characterized morphologically by- simple leaves that are nearly always unequal (oblique) at their base- unisexual flowers in axillary glomerules (or solitary pistillate flowers)- indehiscent drupaceous and usually pubescent fruits with 1 or (more rarely) 2 seeds.
- The Putranjivaceae also contains glucosinolates (mustard oil glycosides).
Other important characters
- Dried leaves are often of a greyish colour.
- Fresh bark and leaves often have a taste of pepper or radish.
Number of genera
- Putranjivaceae are pantropical and comprise ca. 4 genera. In the Neotropics they are represented by 1 genus: Drypetes
- Native - Drypetes.
Govaerts, R., Frodin, G.G. & Radcliffe-Smith, A. 2000. World checklist and bibliography of Euphorbiaceae (with Pandaceae). London: Royal Botanic Gardens, Kew.
Pax, F. & Hoffmann, K. 1922. Drypetes. In: E. Engler (ed.), Das Pflanzenreich IV.147.xv (Euphorbiaceae -Phyllanthoideae-Phyllantheae): 229-279. W. Engelmann, Leipzig.
How to cite
Esser, H.-J. (2009). Neotropical Putranjivaceae. In: Milliken, W., Klitgård, B. & Baracat, A. (2009 onwards), Neotropikey - Interactive key and information resources for flowering plants of the Neotropics. http://www.kew.org/science/tropamerica/neotropikey/families/Putranjivaceae.htm.