| General Description | Oncoba spinosa is a woody, deciduous plant which is either found as a small tree or large shrub. It has thick, light to dark green leaves that alter little in colour during the autumn months. The flower is an attractive white and yellow and is followed by a round, golf-ball sized, hard shelled fruit. The stems, leaves and buds are glaborous while the branches are spiny. |
| ID Characteristic | Flowers are sweet smelling with 8-10 petals and with numerous golden stamens. The fruit is hard shelled, brown when mature and golf-ball sized. The spines can reach 5 cm long. The leaves are green and hairless with a texture similar to leather with coarse toothed margins. |
| Shape | Usually with many branches and flat topped. |
| Landscape | Grown as an accent plant, hedges and screens or for attracting wildlife (birds and butterflies) to the garden. |
| Propagation | Sow fresh seed directly, germination and growth will initially be slow but mature plants can grow as much as 1 m if under irrigation or planted where rainfall is sufficient. The Royal Botanic Gardens, Kew demonstrated a 100% germination rate with fresh seed sown in agar and germinated at 30°C. |
| Cultivation | Grow in full sun, under adequate irrigation growth is accelerated, up to 1 m a year. |
| Pests | None serious. |
| Notable Specimens | Fairchild Tropical Botanical Garden, Miami, Florida, United States of America. |
| Habitat | Found in dry forest edges, dry river valleys, hardpan, mid to low bushland, dry grass savanna Brachystegia woodland and rocky cliffs from sea level to 1800 m.
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| Bark/Stem Description | The bark is smooth and mottled grey with pronounced lenticels. The spines are axillary, single, straight and up to 5 cm long. |
| Flower/Leaf Bud Description | To 2-3 mm in length, glabrous, brown, scaled and ovate to acutely pointed. |
| Leaf Description | The leaves are elliptic, ovate-elliptic or oblong-elliptic, glossy green most of the year and showing no autumn colour. The leaf base is abruptly cuneate while the apex is acuminate and the margins are serrate or serrate-crenate. They can reach up to 12 cm long although typically they are between 6-10 cm in length.
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| Flower Description | The perfect flowers occur individually, terminal or lateral, on short axillary shoots with 4, shortly united at base, concave sepals, half the length of the 8-10 petals that are up to 8- 10 cm long. The petals are white while the stamens and pistil are both a golden yellow colour. The flower is sweet smelling and long lasting. |
| Fruit Description | The fruit is usually 6 cm in diameter, with eight faint longitudinal lines, light to medium green, but red-brown at maturity. It is hard shelled, with the remnant calyx persistent. The fruit contains many, brown, shiny, flattened seeds which are about 4 x 6 mm in size. Fruit can be found on the tree from April to July. |
| Colour Description | The colour of the leaves stays green year long but lightening slightly as the season progresses. Bark is an uninteresting mottled grey year-round. Flowers are white and yellow while the mature fruit is reddish-brown. |
| Texture Description | Medium to fine. |