Halostachys caspica Seeds | Caspian Halostachys
LATIN NAME: Halostachys caspica
COMMON NAME: Caspian Halostachys
Plant Profile
Caspian halostachys is a shrub with almost no leaves to speak of, and the green jointed stems do the work that leaves would do elsewhere. They are erect, much-branched, jointed like a horsetail, and fleshy in cross-section, blue-green when young and turning yellow, then red, in autumn. The leaves are reduced to tiny scales clasping the stem at each joint, so small that they contribute nothing to the plant’s outline and very little to its photosynthesis, which is carried on mainly by the green tissue of the stems themselves.
The flowers are equally reduced: tiny, three together in the notch of each joint, forming narrow spikes along the upper stems in late summer, and they are wind-pollinated and inconspicuous. The whole plant reads as a grey-green thicket of jointed fingers, half a metre to two and a half metres tall, and in autumn the colony turns a dull fire-red before the stems die back. It is native to the salt deserts of the Caspian region, Iran, Central Asia and northwestern China, where it grows on solonchak soils, the crusted, white, waterlogged-then-baked flats that form around evaporating lakes. It is one of the very few woody plants that can hold that ground, and where it establishes it forms almost pure stands.
Science & Biotechnology
Halostachys belongs to the Salicornioideae, the group of amaranths that includes glassworts and samphires, and its anatomy is built around salt. The plant takes up sodium and chloride with the transpiration stream and sequesters them in the large central vacuoles of its stem cells, where they contribute to osmotic adjustment without poisoning the cytoplasm, which is protected by compatible solutes such as glycine betaine and proline. The reduction of the leaves to scales reduces the transpiring surface, and the fleshy stems store water against the dry season. This combination lets the plant maintain turgor and photosynthesis on soils whose osmotic potential would collapse an ordinary crop.
Research on the species has measured its salt accumulation, its biomass production on saline soils, and its capacity to remove sodium from the upper soil profile when the standing crop is harvested and carried away. It has been trialled in phytoremediation and in the revegetation of salt-affected farmland in Xinjiang and Inner Mongolia, usually in mixture with tamarisk, Nitraria and Suaeda. Work on the Salicornioideae has also used the species in phylogenetic studies, since the group’s reduced morphology made its relationships hard to resolve before molecular data, and its position near the base of the subfamily is now reasonably clear.
Uses & Benefits
The plant’s main value is land management. It stabilises the surface of salt flats, traps windblown sand and organic matter, and provides cover and nesting sites in landscapes that are otherwise bare. It is browsed by camels and goats in winter, though the high salt content limits how much stock will take. The stems are cut for fuel where nothing better is available, and the ash has been used locally as a source of soda. In restoration projects it is sown or planted on the margins of saline lakes and along irrigation drains, where its tolerance of both flooding and extreme salinity makes it more reliable than most alternatives.
As a garden plant it is a curiosity rather than a beauty, and it belongs in a dry, saline, exposed site or a gravel garden where its jointed stems and autumn colour can be seen close up. It is not suitable for rich soil or irrigation, where it grows soft and leggy and loses the compact, sculptural quality that makes it interesting. It has no medicinal or culinary use of note, and it should not be confused with the edible samphires, which are annual species of similar appearance. Its value is ecological, and it should be grown on that basis.
Growing from Seed
The seed is very small and must be sown on the surface of a firmed, saline mix. A standard seed compost with an added handful of sea sand or a dilute salt solution works; the species germinates well on saline substrates and is slowed by rich, organic mixes. Scatter thinly, press the seed down without covering, and keep the surface constantly moist with a fine mist. Light is required. Germination begins in one to three weeks at twenty to twenty-five degrees.
Prick the seedlings out into a gritty mix with added sand, and grow them on in full sun with good ventilation, since they are prone to damping off in still, humid air. Plant out into a free-draining, exposed site, and water only until the plants are established. Once the root system is down, the shrub tolerates drought, salinity and short periods of waterlogging. It can also be raised from cuttings taken in summer, which root slowly but reliably in a sandy mix under mist.
Our Take
This is a restoration plant, not a border plant, and it should be judged by what it does to bad ground. Given salt, sun and drainage it will build a stand where little else will grow.
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