Crassula helmsii

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Crassula helmsii

Kingdom:	Plantae
Division:	Magnoliophyta
Class:	Magnoliopsida
Order:	Saxifragales
Family:	Crassulaceae
Genus:	Crassula
Species:	C. helmsii

Binomial name

Crassula helmsii
(T. Kirk) Cockayne

1 Common names
2 Synonyms
3 Origins
4 Description
5 Ecological aspects
6 Cultivation
7 References
8 External links

[edit] Common names

Swamp Stonecrop, New Zealand Pigmyweed

[edit] Synonyms

Tillaea recurva, Tillaea Helmsii, Crassula recurva

[edit] Origins

Originally found in Australia and New Zealand, it has been introduced around the world. In the UK it is considered an invasive species.

[edit] Description

The shoots are rather stiff, carrying narrow parallel-sided leaves in opposite pairs, each leaf being about 4-24mm. Small white flowers with four petals are produced in summer on long stalks arising from the upper leaf axils. The flowers are always above water.

[edit] Ecological aspects

The plant grows on the muddy margins of ponds where it forms carpets with 100% cover, or semi-submerged in deeper water, or totally submerged with elongated stems. It does not die back in winter.^[1]

[edit] Cultivation

C. helmsii is able to grow fully submerged in a cool water aquarium or as a submersed or marginal plant in a pond. Once established it can grow vigorously and may need to be trimmed back. Schedule 9 of the UK Countryside and Wildlife Act 1981 lists this plant as one that cannot be caused to grow in the wild.