Neotropical Tetrameristaceae

Denise Sasaki

Secretaria do Meio Ambiente do Estado de São Paulo, Brazil. 

Description

Trees or shrubs. Leaves simple, alternate (spiral), entire, leathery, glossy, pinnately veined, margins entire, sessile or subsessile, stipules absent. Inflorescences axillary, condensed racemes. Flowers hermaphrodite, actinomorphic; sepals 5, free, with numerous glandular pits adaxially, aestivation imbricate; petals 5, freeaestivation imbricate; stamens 5, free from perianth, filaments flattened, base connate, alternate with petals, anthers basifixed, dehiscing via longitudinal slits; ovary superior, carpels and locules 5, syncarpous, placentation axile, ovule 1 in each locule; style 1, undivided; stigma simple to minutely lobed. Fruits berries, endocarp firm; seeds 4-5, relatively large.

Notes on delimitation

  • Tetrameristaceae is placed in the Theales as a subfamily by Theales by Takhtajan (1997) and Cronquist (1988).
  • According to the APG, Tetrameristaceae does not have close affinities with Theaceae, but does with the Marcgraviaceae (Ericales) (Stevens 2008).

Distribution in the Neotropics

  • There is only one Neotropical genus in the Tetrameristaceae (Pentamerista Maguire), which occurs in the savannas in northern South America (Venezuela, Colombia and Brazil).

Distinguishing characters (always present)

  • Trees or shrubs.
  • Leaves simple, spirally alternate, concentrated at the top of branch.
  • Stipules absent.
  • Inflorescences condensed racemes.
  • Flowers actinomorphic.
  • Flowers 5-merous (sepals 5, petals 5, stamens 5, carpels 5, locules 5, ovules 5).
  • Sepals and petals free.
  • Sepals with glands pits adaxially.
  • Ovary superior.
  • Fruits berries.

Other important characters

Key differences from similar families

  • The Theaceae differs from Tetrameristaceae by having: serrate leaves, usually solitary flowers, numerous stamens, capsular fruits and seeds usually with oblong apical wings.
  • The Pellicieraceae differs from Tetrameristaceae by growing in mangroves and having: buttresses, leaves usually with extrafloral nectaries and woody fruits.

Number of genera

  • Pentamerista Maguire is the only Neotropical genus of the family, with only one species, P. neotropica Maguire.

Useful tips for generic identification

See Distinguishing characters.

Notable genera and distinguishing features

  • There is only one Neotropical genus in the family (Pentamerista).

Status

  • Pentamerista is endemic to northern South America.

General notes

  • According to APG (Stevens 2008), Tetrameristaceae also includes the genus Pelliciera, which is treated separately by Neotropikey (in Pellicieraceae).

Important literature

Cronquist, A. 1993. An intergrated system of classification of flowering plants. Columbia University Press, New York.

Culham, A. 2007. Tetrameristaceae. In: Heywood, V.H., Brummit, R.K., Culham, A. & Seberg, O. (eds.). Flowering Plant Families of the World, p. 318.Royal Botanic Gardens, Kew.

Prince, L.M. & Parks, C.R. 2001. Phylogenetic relationships of Theaceae inferred from chloroplast DNA sequence data. Amer. J. Bot. 88: 2309-2320.

Stevens, P.F. 2008. Angiosperm Phylogeny Website, version 9. http://www.mobot.org/MOBOT/research/APweb/.

Stevenson, D.W.T. 2004. Tetrameristaceae. In: N. Smith, S. A. Mori, A. Henderson, D. W. Stevenson & S. V. Heald (eds.). Flowering Plants of the Neotropics, Pp. 368-369. New York Botanical Garden & Princeton University Press, Princeton.

Takhtajan, A. 1997. Diversity and Classification of Flowering Plants. Columbia University Press, New York.

How to cite

Sasaki, D. (2009). Neotropical Tetrameristaceae. 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/Tetrameristaceae.htm.