Calligonum mongolicum Seeds | Mongolian Calligonum
LATIN NAME: Calligonum mongolicum
COMMON NAME: Mongolian Calligonum
Plant Profile
Mongolian calligonum is a shrub that has solved the desert by giving up leaves almost entirely and doing their work with green stems. What look like stems are in fact the photosynthetic organs: jointed, wiry, almost leafless branches that carry out the work of foliage while losing almost no water. The true leaves are tiny scales at the joints, gone almost before they are noticed. The plant forms a rounded, twiggy bush a metre or two high, with a deep taproot and a wide network of lateral roots that run just below the surface to catch the smallest shower. In spring it produces small, pale pinkish flowers, and these are followed by achenes wrapped in bristly, winged bracts that turn red and roll across the sand in the wind. It grows in the deserts of Mongolia, Inner Mongolia, Gansu and Xinjiang, on mobile dunes and sandy plains.
Science & Biotechnology
Calligonum is a genus of about eighty species, all of them desert shrubs, and it sits in the Polygonaceae — an unexpected placement for a plant that looks like a leafless broom. The green, articulated stems carry out C4-like carbon fixation and have sunken stomata, thick cuticles and a high ratio of surface to volume that together make them one of the most water-efficient photosynthetic systems among desert shrubs. The winged fruit is a wind-dispersal device: the bracts act as a sail, and the whole structure rolls across the sand until it lodges against something, which is exactly how a dune colonist should behave. The genus is taxonomically difficult because species hybridise freely where they meet, and C. mongolicum is one of several that have been examined for the genes behind drought tolerance, with an eye to transferring them to crops.
Uses & Benefits
This is a restoration plant before it is a garden plant. It is one of the core species used in the shelterbelt and sand-fixation programmes across northern China and Mongolia, planted on mobile dunes where nothing else will hold, and its deep roots and wind-resistant stems make it effective at slowing desert advance. The young shoots are browsed by camels and goats in spring, and the woody stems are used for fuel and for weaving rough fencing. It has no significant medicinal use and should not be sold as one, despite the vague claims that circulate about the genus. For gardeners in dry climates it is a curiosity for a sand bed or a large gravel garden, where its leafless green stems and red spring fruit are genuinely unusual.
Growing from Seed
The seed is enclosed in a bristly bract that should be rubbed off before sowing, since it inhibits water uptake. Sow in pure sharp sand, pressed in and barely covered, at 25 to 30 °C; germination is spread over two to five weeks and is rarely complete. Keep the seedlings in full sun from the start and water sparingly — this is a plant that rots at the collar if kept damp. Pot on into deep containers, because the taproot runs, and plant out only on genuinely sandy, free-draining ground. Once established the plant needs no irrigation at all and resents summer water. It is hardy to about minus 25 and tolerates wind, salt and poor soil, but not shade or competition from larger plants.
Our Take
A genuine desert specialist with an important restoration role and a strange, leafless beauty; it wants sand and neglect, not a border.
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