Scientific Name
Crassula helmsii (Kirk) Cockayne
Common Names
Swamp Stonecrop, Australian Swamp Stonecrop, New Zealand Pigmyweed
Synonyms
Bulliarda recurva, Tillaea helmsii, Crassula recurva
Scientific Classification
Family: Crassulaceae
Subfamily: Crassuloideae
Genus: Crassula
Description
Crassula helmsii is a small aquatic or semiterrestrial succulent with round stems, either floating or creeping, with roots forming at the nodes. The leaves are in opposite pairs, narrow and up to 1 inch (2.5 cm) long. Flowers are small, white, with four petals, produced in summer on long stalks that arise from the upper leaf axils. They are always above water.
Hardiness
USDA hardiness zones 9a to 11b: from 20 °F (−6.7 °C) to 50 °F (+10 °C).
How to Grow and Care
Swamp Stonecrop is a stem plant grown both submersed or emersed and as a terrestrial plant. In fact, it must be controlled and watched in pond settings so that it does not escape into the garden.
It provides excellent cover for tadpoles, frogs, and small fish from birds and larger fish as a pond plant. However, it is prone to breaching the pond's surface, even if planted at 2 feet (60 cm) below the surface, which is not an issue, as it allows the plant to flower, with its small white star-like flowers smaller than the stem width.
As an aquarium plant, the stems will thrive and should be treated as any other stem plant, pinched off at the top when they grow higher than required, and the tops replanted to prevent them from breaking the surface.
This is an extremely vigorous plant, forgiving of many climate conditions. It grows throughout most of the year with minimal winter dieback.
Origin
Crassula helmsii is native to Australia and New Zealand.
Links
- Back to genus Crassula
- Succulentopedia: Browse succulents by Scientific Name, Common Name, Genus, Family, USDA Hardiness Zone, Origin, or cacti by Genus
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