Neotropical Saururaceae

Paul J.M. Maas & Hiltje Maas-van de Kamer

National Herbarium of the Netherlands (Wageningen branch), Wageningen, the Netherland

Description

Herbs, aquatic or in marshy habitats, perennial, rhizomatous, aromatic.  Leaves simple, alternate, basal, venation palmate; stipules fused to the petioleInflorescences terminal or leaf-opposed spikes or racemes with a basal involucre of several white bracts (Anemopsis).  Flowers actinomorphic, bisexual, whitish, small; perianth absent; stamens 6-8, anthers dithecal, longitudinally dehiscent, basifixed, introrse; gynoecium composed of 3-5 carpels, these connate only at the base (Saururus) or united into a 1-locular, inferior ovary sunken in the axis of the inflorescence (Anemopsis), styles 3-5 each with 1 stigma, placentation axile or parietal, ovules 1-10 per loculeFruits composed of 3-4 indehiscent, more or less fleshy carpels, each carpel 1-seeded (Saururus) or several-seeded capsules (Anemopsis).  Seeds few to many, small.

Notes on delimitation

  • The Saururaceae are placed in the order Piperales, close to the Piperaceae (Cronquist 1981; Stevens, 2008; APG III, 2009; Takhtajan 2009).

Distribution in the Neotropics

This primarily North Temperate family comprises five genera and six species in Asia and North America, extending to the Neotropics with two genera and two species, from tropical Florida to Mexico, in marshes, bogs, and other moist places up to an elevation of 1,900 m.

  • Anemopsis Hook. & Arn. (1 sp., A. californica (Nutt.) Hook. & Arn.)  southern USA to Queretaro in Mexico.
  • Saururus L. (1 sp., S. cernuus L.)  Canada to Texas and Florida.

Distinguishing characters (always present)

  • Aquatic, aromatic herbs.
  • Leaves alternate, basal, rather fleshy; stipules small and fused to the petioles.
  • Inflorescences racemes or spikes, and flowers without perianth.

Key differences from similar families

Differences from Piperaceae:

1.  Aquatic or marshy herbs; leaves basal, bracts non-peltate; stamens 6-8 …. Saururaceae

1.  Non-aquatic shrubs, trees, or herbs; leaves evenly spread over the whole stem; bracts peltate; stamens 2-6 …. Piperaceae.

Useful tips for generic identification

Key to genera of Neotropical Sauraceae

1.  Inflorescence with a basal involucre of white bracts; gynoecium syncarpous; fruit a capsule …. Anemopsis
1.  Inflorescence without a basal involucre of bracts; gynoecium almost apocarpous, the carpels being connate only at the base; fruit fleshy …. Saururus

Status

  • The two genera are native in the Neotropics.
  • Saururus cernuus is used as an ornamental in aquaria and ponds.
  • Pollinated by insects, mainly syrphids.

Important literature

A.P.G. III. 2009. An update of the Angiosperm Phylogeny Group classification for the orders and families of flowering plants: APG III. Bot. J. Linnean Soc. 161: 105-121.

Cronquist, A. 1981. An integrated system of classification of flowering plants. Columbia University Press. New York

Lentz, D.L. 2004. Saururaceae. In: Smith, N.P., Mori, S.A., Henderson, A., Stevenson, D.W., and Heald, S.V. (eds.). Flowering plants of the Neotropics. p. 346. Princeton University Press, Oxford and Princeton.

Maas, P.J.M. & Westra, L.Y.Th. 2005. Neotropical Plant Families. A concise guide of vascular plants in the Neotropics. 3rd ed., p. 176. A.R.G. Gantner Verlag K.G., Ruggell.

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

Takhtajan, A. 1997. Flowering Plants. Second edition. Springer Verlag, Berlin.

Wu Cheng-Yih and Kubitzki, K. 1993. Saururaceae. In: Kubitzki, K. Rohwer, J.G., and Bittrich, V. (eds.). The families and genera of vascular plants. Vol. 2. Flowering Plants - Dicotyledons. Magnoliid, Hamamelid, and Caryophyllid Families, pp. 586-588. Springer Verlag, Berlin, etc.

How to cite

Maas, P.J.M. & Maas-van de Kamer, H. (2012). Neotropical Saururaceae. 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/Saururaceae.htm.