Description: Submerged or emergent aquatic perennials with linear submerged leaves and petiolate floating leaves; tuberous or rhizomatous.
Leaves all basal, margins entire or crisped.
Inflorescence emergent, simple or branched spatheate spikes; spathes persistent or falling early. Flowers usually zygomorphic, bisexual [or rarely unisexual and then plants dioecious]. Perianth segments 1–6, yellow, greenish yellow, or white. Stamens 6 or more, in whorls of 3; anthers 2-locular, extrorse or latrorse, dehiscing by longitudinal slits. Carpels superior, free [or basally coherent], 3–6, mostly sessile; each carpel with ovary narrowed into a style with an inner stigmatic ridge; ovules 1–8 per ovary.
Individual fruit a follicle; each with 1–several seeds. One species sometimes viviparous.
Distribution and occurrence: World: over 50 species, mostly Africa & Madagascar. Australia: 12 species (11 species native, 1 species naturalized), all mainland States.
Text by S. W. L. Jacobs (1993); edited KL Wilson (Sep 2011). Key modified from Jacobs et al. 2006 Telopea 11(2) 129-134 by K.L.Gibbons, 22 June 2020
Taxon concept:
| | Key to the species | |
| 1 | Inflorescence yellow, usually a simple spike, rarely with smaller lateral branches below | 2 |
| Inflorescence white, normally with 2 more or less equal branches | Aponogeton distachyos |
| 2 | Plants mainly producing floating leaves; floating leaves mostly cordate at base; seeds with obvious double testa; flowers usually widely spaced | Aponogeton queenslandicus |
| Plants mainly producing submersed leaves or submersed and floating leaves; floating leaves mostly obtuse, some cuneate or truncate at base; seeds with a single testa or, if double, the second seed coat closely adhering and difficult to detect; flowers closely or widely spaced
Back to 1 | Aponogeton elongatus |
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