Portulacaria afra

It is a soft-wooded, semi-evergreen upright shrub or small tree, usually 2.5–4.5 metres (8–15 ft) tall. Similar in appearance to the unrelated "jade plant" Crassula ovata (family Crassulaceae), P. afra has smaller and rounder pads and more compact growth (shorter internodal spaces, down to 1.5 millimetres (0.059 in)). It is much hardier, faster growing, more loosely branched, and has more limber tapering branches than Crassula once established.[1]

The genus Portulacaria has been shown to be an outlier, relatively unrelated to the other genera in the family, which are all restricted to small ranges in the arid far west of Southern Africa.[2]

It is very widespread in the east of South Africa (including Eswatini). In this moist climate, it is relatively rare, and tends to favour dryer rocky outcrops and slopes.

It is also found in much denser numbers in the dryer southern Cape. Here it occurs from the Little Karoo of the Western Cape, eastwards up until the thicket vegetation of the Eastern Cape.[3] Spekboom is found most prolifically in the Albany thickets, a woodland ecoregion, which locally is often called noorsveld, after the high number of succulent Euphorbia species, which are often called noors plants. [4]

"Prostrata" decumbent variety

In the wilds of South Africa, large plants do survive the winter frosts by growing dense enough to provide their own natural cover. Drought-tolerant and fire-resistant, it will endure desert sun and heat once established, which the jade plant will not. Portulacaria is a common landscape plant in Phoenix, Arizona and southern California. Cuttings root very easily in most potting media.

Ornamental

P. afra cultivated as a bonsai

It is popular as a specimen for bonsai, and as a hardy xeriscaping plant. Several varieties exist - some bred in cultivation, others naturally occurring:[5]

• "Limpopo": A variety with much larger leaves. It is the natural form from the far north of the species' range.
• "Prostrata": A low-lying, decumbent form that is frequently used as a ground-cover.
• "Aurea": A compact, upright form with rounded leaves that go bright yellow in the sun.
• "Foliis variegatus": A variegated form.
• "Medio-picta": Variegated with a lighter centre.