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Cabombaceae Rich. ex A. Rich. Search in IPNISearch in NYBG Virtual Herbarium Decrease font Increase font Restore font
 

Published In: Dictionnaire classique d'histoire naturelle 2: 608. 1822. (31 Dec 1822) (Dict. Class. Hist. Nat.) Name publication detail
 

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CABOMBACEAE (Water Shield Family)

Contributed by Alan E. Brant

Plants perennial herbs, with short rhizomes (seldom collected) giving rise to long (to 2 m or more) branched stems potentially rooting at the nodes. Leaves opposite and/or alternate, with well-developed, mostly long petioles. Stipules absent. Leaf blades simple and entire or highly dissected. Flowers solitary in the leaf axils, mostly long-stalked, hypogynous, perfect, actinomorphic. Perianth showy, appearing free, the sepals and petals fused only at the very base, persistent at fruiting. Sepals 3 or 4. Petals 3 or 4. Stamens 3–6 or numerous, free, the filament slender and flattened, attached at the anther base. Pistils (1–)2–18, each with 1 carpel, the ovary superior, with 1–5 ovules. Style 1, the stigma capitate or a linear region toward the style tip. Fruits in a ring or cluster, achenelike, indehiscent, leathery. Seeds 1–3. Two genera, 6 species, worldwide.

Genera of Cabombaceae were included in the Nymphaeaceae by Steyermark (1963) and other earlier authors, but most botanists now agree that Cabomba and Brasenia constitute an independent family, based on a variety of morphological and biochemical characters. Both groups comprise aquatics with submerged and/or floating leaves.

The interesting floral biology of the two species present in Missouri has been studied in detail (Schneider and Jeter, 1982; Osborn and Schneider, 1988). Brasenia schreberi is primarily wind pollinated, and although a number of bees and wasps visit the flowers of Cabomba caroliniana, it is mainly fly-pollinated. In both species, individual flowers are open for only two days. On the first day, the stigmas become receptive as the flower opens at mid-morning; in the late afternoon, the flower closes and the flower stalk bends, resulting in the submergence of the flower overnight. On the second morning, the flower emerges from the water again, and although the stigmas are no longer receptive, the stamens elongate slightly and shed their pollen. The second evening, the flower again closes and become submerged, with fruit development occurring underwater. Thus, first-day flowers are cross-pollinated with pollen from second-day flowers.

 

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1 1. Submerged leaves absent, or if present in young plants, then entire and peltate (similar to floating leaves); floating leaves present during entire growing season, 511 cm long, conspicuous, peltate, not dissected; submerged parts covered with a thick layer of a jellylike mucilaginous substance ... 1. BRASENIA

Brasenia
2 1. Submerged leaves deeply and finely dissected, not peltate; floating leaves present only at flowering, 0.62.0 cm long, relatively inconspicuous, peltate, not dissected; submerged parts only slightly if at all coated with a mucilaginous substance ... 2. CABOMBA Cabomba
 
 
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