Oxalis triangularis
Oxalis triangularis
Safety & Hazards
The leaves contain oxalic acid, which gives them their sharp flavour. Perfectly all right in small quantities, the leaves should not be eaten in large amounts since oxalic acid can bind up the body's supply of calcium leading to nutritional deficiency. The quantity of oxalic acid will be reduced if the leaves are cooked. People with a tendency to rheumatism, arthritis, gout, kidney stones or hyperacidity should take especial caution if including this plant in their diet since it can aggravate their condition[1].
Cultivation Details
Oxalis triangularis is not very cold-hardy in the temperate zone, tolerating temperatures down to about -3°c[2]. The plant has survived outdoors on our Cornwall site (hardiness zone 8) for several years in a well-drained, moderately heavy soil and a sunny position[PFAF]. It should be possible to grow the plant outdoors even in somewhat colder areas by digging up the roots in the autumn after the top growth has been cut down by frosts, storing them in a cool but frost-free place and replanting them in mid to late spring[PFAF]. Easily grown in a sandy soil in a warm dry position in sun or light shade[3, 4]. Grows well in a dry shady corner[2]. There are two main forms of this plant, ssp triangularis has smaller, green leaves and is, in our experience, slightly the hardier of the two. Ssp papilionacea has larger, dark purple leaves and is considered the more ornamental[PFAF].
Propagation
Seed - best sown as soon as it is ripe in a cold frame. The seed from one subspecies does not always come true - on at least one occasion we have had the purple-leaved form grow from seed of the green leaved form that had definitely not been cross-pollinated[PFAF]. Prick out the seedlings into individual pots when they are large enough to handle and grow them on in a greenhouse for their first winter. Plant them out in late spring or early summer. Division in spring. Larger divisions can be planted out direct into their permanent positions. We have found that it is better to pot up the smaller divisions and grow them on in light shade in a cold frame until they are well established before planting them out in late spring or early summer. Cite as: Temperate Plants Database, Ken Fern. temperate.theferns.info. 2026-02-21. <temperate.theferns.info/plant/Oxalis+triangularis>
Pollinators
Insects
References
- [1]Encyclopaedia of Herbs and their Uses. — Bown. D. · Dorling Kindersley, London. · 1995 · ISBN 0-7513-020-31 ↩︎A very well presented and informative book on herbs from around the globe. Plenty in it for both the casual reader and the serious student. Just one main quibble is the silly way of having two separate entries for each plant.
- [2]Conservatory and Indoor Plants Volumes 1 & 2 — Phillips. R. & Rix. M. · Pan Books, London. · 1998 · ISBN 0-330-37376-5 ↩︎Excellent photos of over 1,100 species and cultivars with habits and cultivation details plus a few plant uses. Many species are too tender for outdoors in Britain though there are many that can be grown outside.
- [3]RHS Dictionary of Plants plus Supplement. 1956 — F. Chittendon. · Oxford University Press · 1951 · ISBN - ↩︎Comprehensive listing of species and how to grow them. Somewhat outdated, it has been replaced in 1992 by a new dictionary (see [ 200 ]).
- [4]The New RHS Dictionary of Gardening. 1992. — Huxley. A. · MacMillan Press · 1992 · ISBN 0-333-47494-5 ↩︎Excellent and very comprehensive, though it contains a number of silly mistakes. Readable yet also very detailed.
- [PFAF]Plants for a Future — pfaf.org ↩︎