Jon L.R. Every
Royal Botanic Gardens, Kew, UK.
Evergreen trees (2-30 m tall) and scandent shrubs, large prop roots regularly present, glabrous or with non-glandular trichomes, all parts strongly aromatic. Leaves simple, opposite, decussate, petiolate, petiolar bases form a cylindric or quadrangular persistent sheath around the stem, nodes swollen; blade fleshy to coriaceous, pinnately veined, margins crenate-serrate; stipules 4. Staminate inflorescence in dioecious species (axillary or terminal, 1 to several spikes, axis racemose or paniculate; leaf-like bracts present), in monoecious species (solitary spikes on pistillate inflorescence axis or within a cymules (along with pistillate flowers)). Pistillate inflorescence axillary or terminal, cymules, spikes, racemes or panicles; bracts present. Staminate flowers basic, 60-300 flowers per spike, without perianth, ebracteate, 1-3 sessile stamens, anthers, oblong, longitudinally dehiscent. Pistillate Flowers simple, perianth lobes 0.5-3mm, free at the base or partially to completely united forming a small tube, adnate to the ovary; ovary inferior or semi-inferior, sometimes nude, carpel 1, locule 1, stigma 1 sessile or on very short style. Fruit a drupe, fleshy, aromatic and brightly coloured, exocarps thin, mesocarp fleshy, endocarp hard, or multiple with colourful, juicy floral bracts. Seed 1 per fruit, small, brown or black smooth or minutely papillate, endosperm well developed, oily.
Notes on delimitation
- Chloranthaceae are probably sister to magnoliids (Moore et al. 2007) as the only family in the order Chloranthales.
Distribution in the Neotropics
- Growing throughout the Neotropics, predominantly in wet, cool, montane forest at altitudes anywhere between 500m and 3,000m.
- Two-thirds of the species are found in Andean South America, primarily in disturbed sites.
Distinguishing characters (always present)
- Swollen leaf sheath in-between leaf stalks.
- Unisexual flowers.
- Minute perianth.
- Opposite leaves.
- Crenate to serrate leaf margins.
- NB! Pungent odour from all broken parts of the plant.
Other important characters
- Prop roots.
- Floral bracts becoming colourful and succulent and appealing to birds.
- Long flowering season.
- Long staminate inflorescences with abundant pollen.
Key differences from similar families
- Loranthaceae are estipulate.
- Caprifoliaceae have a distinct perianth.
- Piperaceae have alternate leaves.
Number of genera
- One: Hedyosmum Sw. with 44 species.
- Hedyosmum brasiliense has medicinal property.
- One species H. mexicanum C. Cordem. provides edible, sweet tasting fruit.
- Hedyosmum is derived from the Greek words hedy (pleasant) osmum (smelling).
- An interesting family from an evolutionary point of view, lending its name to the Chloranthoid Hypothesis, which suggests that the first flowering plants had the similar small, basic, unisexual, wind-pollinated flowers.
Maas, P. J. M. & Westra, L. Y. Th. 2005. Neotropical Plant Families. 3rd ed. P. 106. A.R.G. Gantner Verlag K.G., Ruggell.
Moore et al. 2007. Using plastid genome-scale data to resolve enigmatic relationships among basal angiosperms PNAS: 104(49).
Todizia, C. A. 1988. Chloranthaceae: Hedyosmum. Flora Neotropica. Monograph 48. The New York Botanical Garden, New York.
How to cite
Every, J.L.R. (2009). Neotropical Chloranthaceae. 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/Chloranthaceae.htm.