Alismatales

Alismataceae
Aponogetonaceae
Araceae
Butomaceae
Cymodoceaceae
Hydrocharitaceae
Juncaginaceae
Limnocharitaceae
Posidoniaceae
Potamogetonaceae
Ruppiaceae
Scheuchzeriaceae
Tofieldiaceae
Zosteraceae

The order Alismatales contains the alismatids, a group of monocotyledons (class Liliopsida). The order contains about 165 genera in 14 families, with cosmopolitic distribution. Most families are comprised of herbaceous non-succulent plants. These plants are commonly found in aquatic environmments. The flowers are usually arranged in inflorescences, and the mature seeds lack endosperm.

Traditionally, the order Alismatales was restricted to contain just three families (Alismataceae, Butomaceae and Limnocharitaceae). The other families were not considered as alismatids, and were assigned to various distinct orders, but this approach produced polyphyletic groups, and so the whole group of families is now placed into a single order.

The Petrosaviaceae have been placed in this order, but their actual affinity is not so clear. The alismatids have been considered the sister group of the Arales and the latter are now included here. As a result of this merger, the Araceae became the most important family in the order, accounting alone for over 2000 species in about 100 genera. The rest of families contain together just about 500 species.

See also

• Seagrass

References

• B. C. J. du Mortier (1829). Analyse des Familles de Plantes : avec l'indication des principaux genres qui s'y rattachent, 54. Imprimerie de J. Casterman, Tournay.
• W. S. Judd, C. S. Campbell, E. A. Kellogg, P. F. Stevens, M. J. Donoghue (2002). Plant Systematics: A Phylogenetic Approach, 2nd edition. pp. 242-247 (Alismatales). Sinauer Associates, Sunderland, Massachusets. ISBN 0878934030.