CPV #3: Silver Tree – Burn to Live
The cache, a black-taped tablet pot, is hidden at this popular wine estate, near a distinctive, beautiful, rare, endangered and protected tree . . .
To find the cache: click on the image above which will give you access to a jigsaw puzzle. The cache coordinates and hint will be revealed on completion of this.
The silver (leaf) tree (Leucadendron argenteum), known in Afrikaans as Witteboom or Silwerboom, is an endangered fynbos species in the Proteaceae family, endemic to a small area of the Cape Peninsula.
This enormous Protea is naturally confined to a tiny area in and around Cape Town. Its main population grows on the slopes of Table Mountain, especially around Lion's Head, above Rhodes Memorial and the mountain slopes above Kirstenbosch National Botanical Garden.
There are also 4 tiny outlying populations in Stellenbosch, Somerset West (in Silvertree Gorge or Silwerboomkloof, a natural heritage site in the Spanish Farm suburb), Paarl and Constantia (on the lower eastern slopes of Vlakkenberg). It is not known whether these occur naturally or were planted in early Cape history.
Historically, it was widespread on Table Mountain, covering its slopes in shimmering silver forests. However, early demand for timber led to much of these forests being felled and now it is a rare and endangered species.
It is a striking evergreen tree, growing 5–7m tall (sometimes up to 16 m). It is erect and well-proportioned with a thick, straight trunk and grey bark. The soft, silky leaves are shiny silver, lanceolate, 8–15cm long and 2cm broad with a distinctive silvery sheen produced by dense velvety hairs.
The intensity of the sheen varies with the weather. They are at their most silver in hot, dry weather, when 
the hairs lie flat to protect the leaves from drying out. In wet weather they are not quite as dazzling, as the hairs stand more erect to allow for free air circulation.
The insect and wind-pollinated flowers are produced in dense globose inflorescences 4-5 cm diameter, and give off a pleasant scent. Like all Leucadendrons, it tree is dioecious, with separate male and female plants - see excellent illustrated blog here. The male trees are more showy, they flower more prolifically, the involucral bracts shine bright silver and the flower heads are bright yellow balls that seem to glow inside the silver leaves.
The fruit is a heavy woody cone, containing numerous seeds, each a small nut with a silky-haired helicopter-like parachute, enabling it to disperse by wind. After germination it pushes up two green, bare 
and leathery cotyledons.
Due to urban development, inappropriate fire management, and invasive alien trees like pines and gums, silver trees have been driven from about 74% of their natural range. Mortality of these short-lived trees is negligible after a burn, but then increases to about 5% per annum.
During a longer-term absence of burns however, sudden die-offs may occur, even in a matter of hours. These are probably the combined result of (warm) berg winds and diseased roots weakened by Phytophthora root rot which inhibits their water absorption.
Around 40-50% of the trees burned in the 26-27/1/06 fire. As seedlings only occur naturally after fire, this was a necessary stage in the life-cycle of the tree, and the population has recovered totally.
A major deterrent to propagation of this tree is its short life span - most don't live over 20 years. This 
doesn't affect their conservation however, as fires rejuvenate populations on average every 15–20 years by killing the surviving adults and triggering the release of the canopy seed bank (in the cones), and germination of the soil seed bank. Seeds remain viable for at least 80 years. Juveniles take 5–7 years to flower and set seed, after which the trees are ready to burn again.
See here for more info on this lovely tree.
Permission for the cache was kindly given by CPV management.