What’s a dichotomous key?
Help
- Group 1Lycophytes, Monilophytes
- Group 2Gymnosperms
- Group 3Monocots
- Group 4Woody angiosperms with opposite or whorled leaves
- Group 5Woody angiosperms with alternate leaves
- Group 6Herbaceous angiosperms with inferior ovaries
- Group 7Herbaceous angiosperms with superior ovaries and zygomorphic flowers
- Group 8Herbaceous angiosperms with superior ovaries, actinomorphic flowers, and 2 or more distinct carpels
- Group 9Herbaceous angiosperms with superior ovaries, actinomorphic flowers, connate petals, and a solitary carpel or 2 or more connate carpels
- Group 10Herbaceous angiosperms with superior ovaries, actinomorphic flowers, distinct petals or the petals lacking, and 2 or more connate carpels
- You are here:
- Dichotomous Key
- Elatinaceae
Elatinaceae
This family contains exactly one genus, Elatine.
See list of 3 species in this genusReference: Fernald (1941).
-
1a. Placentation basal-axile, therefore, the ovules/seeds all set at approximately the same level in the ovary/fruit; seeds marked with transversely elliptic, round-ended areoles, the ends of the areoles more or less meeting the other ends (i.e., not dovetailed with them), therefore, the longitudinal ridges of the seed appearing straight and distinct [Fig. 607]; leaf blades 0.7–5 mm long; perianth 2-merous; flowers with 2 stamens
-
1b. Placentation axile, therefore, the ovules/seeds set at different levels in the ovary/fruit; seeds marked with transversely elongate, 6-sided, angular-ended areoles, the ends of the areoles alternating and dovetailed with areole ends from the adjacent rows, therefore, the longitudinal ridges of the seed broken and less conspicuous [Fig. 606]; leaf blades 2.8–8 (–15) mm long; perianth (2–) 3-merous; flowers with (2–) 3 stamens
-
2a. Leaf blades obovate to broad-spatulate, usually rounded at the apex, the larger 1.5–5 mm wide; seeds borne from the lower half of the ovary’s central axis, ascending
-
2b. Leaf blades linear to lanceolate or narrow-spatulate, truncate or retuse at the apex, 0.5–3 mm wide; seeds borne throughout the length of the ovary’s central axis, divergent
-
Show photos of: Each photo represents one species in this genus.