Eleocharis pusilla ('E. parvula')

Compared with the long-known Eleocharis acicularis under equal conditions, it is shorter (usually noticeably under 10 cm), a lighter green, and its stems curve sideways. Spikerush species are hard to tell apart: without spikelets they are practically impossible to identify, so it is not out of the question that more than one species is sold under the 'E. parvula' label (a very similar Eleocharis sp. 'Belem' is known in the US). It can also be confused with a stunted E. acicularis.

As for the species: easy, growth medium, light medium to strong, CO₂ 6–40 mg/l, temperature 20–25 °C. Forms a grassy lawn, propagates by runners and by division.

Nano aquarium, foreground in a group and as a carpet.

A species native to Australia and New Zealand, from damp places. Imported from Australia, on sale since 1997 — most often under the 'Eleocharis parvula' label. But E. pusilla and E. parvula are not synonyms but two different species: true E. parvula grows in Europe, North Africa, Asia, North and Central America, mostly in brackish coastal places, and bears small spindle-shaped tubers, curved in a J or U shape, at the ends of its rhizomes. The aquarium 'dwarf spikerush' has no such tubers. So the aquarium plant sold as 'E. parvula' is, as a rule, actually Eleocharis pusilla, and true E. parvula is most likely absent from the trade.