Common Name: Water Hawthorn

General Information

Water hawthorn is a very ornamental, perennial plant that is often grown in the ponds of gardens in warm temperate to tropical regions[]. The plant can grow up to 60cm above the water, spreading to form clumps 120cm or more wide[].
The plant is a well known local delicacy for the cold winter months in South Africa[]. It is sold in local markets and has become so popular that many commercial plantings have been made in ponds around the western Cape[]. The plant is also often grown as an ornamental.

Known Hazards

None known

Botanical References

Range

Southern Africa - southwestern Cape Province.

Habitat

Pond margins in water 15 - 60cm deep[]. Plants grow in ponds that dry up in the hot summer months[].

Properties

Edibility Rating
Medicinal Rating
Habit	Perennial
Height	0.60 m
Cultivation Status	Cultivated, Ornamental, Wild

Cultivation Details

A plant of the warm temperate and subtropical zones, where it is found at elevations up to 1,500 metres. It grows best in areas where annual daytime temperatures are within the range 12 - 18°c, but can tolerate 10 - 24°c[]. Mature plants can be killed by temperatures of -5°c or lower, but new growth is badly damaged at 0°c[]. It prefers a mean annual rainfall in the range 600 - 1,100mm, but tolerates 500 - 1,200mm[].
A water plant, growing in water 15 - 60cm deep. It can also grow in wet soil but is then very restricted[]. It requires a rich soil[]. Thrives in clay and loamy soils[]. Prefers a pH in the range 6 - 7.5, tolerating 4.5 - 8[]. Succeeds in full sun and under partial shade[]. Plants are adapted to growing in ponds that dry up in the heat of summer - the plants become dormant at this time, coming back into growth when the winter rains fill up the ponds[].
The flowers have a hawthorn-like scent[].

Edible Uses

Tuber - roasted[, ]. Starchy[]. Considered to be a great delicacy[].

Flowering spike - pickled or used as a spinach or asparagus substitute[, , , , , , ]. A very popular food in South Africa[].

The young shoots are used as an asparagus substitute[, ].

The flowers are used as a flavouring[].

Medicinal

The stalks have medicinal properties[].
The stems with their high juice content make soothing treatments for burns and scrapes and take the pain out of sunburn, if the juice is applied every hour until the redness fades[].

Other Uses

None known

Propagation

Seed - best sown in a pot as soon as it is ripe and kept emmersed in 3cm of water. The seed can also be stored in water and sown in spring[]. It usually germinates in 1 - 2 months at 20°c[]. When large enough to handle, prick the seedlings out into individual pots and grow them on in just covered in water in a greenhouse for their first winter. Plant them out in late spring or early summer, after the last expected frosts. In its native environment, the seeds germinate whilst floating in the water - in this case the seedlings can be gathered up, planted into pots and then planted out into their permanent positions when large enough[]. Plants can flower in their second year of growth from seed[].
Division can be carried out at any time in the growing season, though mid to late spring is probably best. The divisions can be planted straight out into their permanent positions.