Restio quadratus Mast.
Common names: square-stem restio, flats restio (Eng.) vlakteriet (Afr.)
Restio quadratus is a tall reed-like plant with a spreading habit.
The mature stems (culms) are thick and square in shape with clusters of sterile branches at the nodes. The young culms look very attractive with dark green, soft and fluffy looking foliage.
Even though most restios adapt very well to a regime with little or no watering during summer, Restio quadratus has to have regular water to look at its best.
This is a plant for large gardens because the plants are not only tall, up to 2 m in height, but can also easily attain a diameter of 1.5 m at ground level. The stems are upright and slightly curved at the top, where most of the clusters of sterile branches are situated. The flowers are small and white but the female plants provide more of a show than most restios, as they flower profusely for a short, concentrated time in July or August.
The mature plants of Restio quadratus look very similar to Calopsis paniculata, but can easily be distinguished by the square stems. These two species, although from two different genera, do not only look very similar with their spreading habit and nearly the same height, but also flower and fruit at more or less the same time.Apart from the stems, the other big difference is in the shape of the seed. C. paniculata seed is a very small nut in an indehiscent ovary, whereas the seed of R. quadratus is much larger, a small, barrel-shaped, dark brown nut, dropping out of the inflorescence as soon as it is ripe.
Derivation of name and historical aspects
The latin species name of quadratus refers to the very distinctive thick, square stem. The common name of 'vlakteriet' refers to the large plains or 'vlaktes' where this species grows in damp localities, often near seeps.
This species is wind pollinated and releases a large quantity of pollen during the flowering period.
If Restio quadratus has any economic value, it would be as material for making brooms. The long, feathery stems are an attractive dark green in colour and could be used in the cut foliage industry. The species is valuable in its function as a soil binder in the seepage areas in the mountains, where it protects the catchment areas.
Growing Restio quadratus
The plants are best grown from seed, which should be treated with smoke or 'Instant Smoke Plus' seed primer. The seeds have a good rate of germination. This species grows best in a position in full sun, in a well-drained but moist soil and needs plenty of air movement around it. When the plants are grown in light shade they look quite attractive, stay smaller and very feathery and do not produce much seed. The plants adapt to a large variety of soil types.
The best time for planting restios is at the beginning of the rainy season, as the plants need regular watering during the first six weeks to two months after planting. The plants need a normal garden watering regime and are not suitable for dry gardens. They may be fed with standard seaweed-based organic fertilizers, or by sprinkling the surrounding soil with a small amount of ammonium sulfate during the growing season. When the stems are three years old, they start dying down and should be removed at ground level. This is the only maintenance required, the plants should not be pruned back by shortening the stems, as this weakens the plants.
- DORRAT-HAAKSMA, E.& LINDER, H. P. 2000. Restios of the Fynbos. The Botanical Society of South Africa, Cape Town.L
- LINDER, H.P. 1985. Conspectus of the African species of Restionaceae. Bothalia 15: 387-503.
- LINDER, H.P. 1991. A review of the southern African Restionaceae. Contributions from the Bolus Herbarium 13.
- LINDER, H.P. April 2001. The African Restionaceae. Contributions from the Bolus Herbarium 20 (on CD Rom).
- BROWN, N., JAMIESON, H. & BOTHA, P. 1998. Grow restios. Kirstenbosch Gardening Series, National Botanical Institute, Cape Town.
Kirstenbosch National Botanical Garden
Plant Type: Restio
SA Distribution: Western Cape
Soil type: Sandy, Loam
Flowering season: Winter
PH: Acid, Neutral
Flower colour: Brown
Aspect: Full Sun
Gardening skill: Average