Iron Cross Plant
Oxalis deppei
Family: Oxalidaceae
What it is like
Oxalis deppei is a BULB growing to 0.3 m (1ft) by 0.1 m (0ft 4in). See above for USDA hardiness. It is hardy to UK zone 8 and is frost tender. It is in flower from June to November. The species is hermaphrodite (has both male and female organs) and is pollinated by Insects. Suitable for: light (sandy) and medium (loamy) soils and prefers well-drained soil. Suitable pH: mildly acid and neutral soils. It cannot grow in the shade. It prefers moist soil.
Height (m): 0.3
Where it is found
Not known
Southern N. America - Mexico. Occasionally established in Europe.
Conservation Status:
Countries/locations it is found in
How it is used
Food
Rating: 4
Leaves and flowers - raw or cooked. A delicious lemony flavour, the leaves are tender and fairly free of fibres even when they get older. Both the leaves and the flowers make a very refreshing and thirst-quenching munch in the garden, they also make an excellent flavouring in salads. The leaves are available from June to October and the flowers from July to October, or even later in mild autumns. Use in moderation, see notes at top of sheet. Root - raw or cooked. The roots are up to 10cm long and 3cm wide at the top, they are tender and juicy but usually insipid. Occasionally the root has a pleasant acid flavour, we have yet to find out what causes the difference.
Root: includes bulbs, corms, tubers, rhizomes etc.
Medicine
Rating: 0
Other
Rating:
How it is grown
An easily grown plant, preferring a sandy soil in a warm dry position. It dislikes dry or heavy soils. Dislikes lime. Prefers a southerly aspect. This species is only hardy outdoors in the milder areas of Britain, tolerating temperatures down to about -5°c or perhaps a bit lower if the soil is very well-drained. The bulbs are easily harvested in late autumn, however, and can be stored overwinter in a cool frost free place, replanting them in the spring. In milder winter areas a good mulch is usually sufficient to see the bulbs through the winter and they will then normally be more productive of leaves and flowers in the following year. Plants have survived the winter for several years without a mulch on our trial grounds in Cornwall. A very ornamental plant, flowering freely all summer. It was formerly cultivated in Mexico for its edible tuber (this may be a mistaken entry that should have referred to O. tuberosa. Whilst the root of this plant is edible it is neither productive nor very flavourful. The leaves and the flowers are far superior). This species is closely related to and probably part of O. tetraphylla, differing only in its sessile bulbils and truncate leaves.
Propagating it: Seed - best sown as soon as ripe in a cold frame. Prick out the seedlings into individual pots when they are large enough to handle and plant them out in late spring or early summer. Our plants have never produced seed. Division in autumn, harvest the bulbs and replant in the spring. They usually increase very freely.
Best place to grow: Cultivated Beds;
Habit: Bulb
Hardiness: 7-10
Growth:
Soil: Light (sandy), medium
Shade: No shade
Moisture: Moist
Things to keep in mind
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.