Leucospermum conocarpodendron

L. conocarpodendron is an evergreen large shrub of high and in diameter with a rounded crown, which is rigid because of the thick branching at approximately right angles, and with a firm trunk of in diameter that is covered by thick greyish, reddish or blackish bark with a netting of fissures. The flowering branches are rigid, 1–1½ cm (0.4–0.6 in) thick and covered with a dense layer of white or greyish crinkly hairs or long soft silky hairs. The leaves lack a leaf stalk and stipules, ovate to lance-shaped with the greater width often beyond midlength 6–11½ cm (2.4–4.6 in) long and 2½–5 cm (1–2 in) wide, with a blunt or pointy tip, shallow or deeply incised with three to ten teeth. Dependent on the subspecies, the surface of the leaves is either hairless or has a dense covering of soft, greyish, convoluted hairs, occasionally with a fringe of fine hairs. Differences between the subspecies The grey tree pincushion or vaalkreupelhout in Afrikaans (subsp. conocarpodendron) has felty hairy leaves due to a dense cover of fine crisped hairs, while the green tree pincushion or groenkreupelhout (subsp. viridum) has green hairless adult leaves, sometimes with a fringe of hairs around the edge. At one location, on the east side of Little Lion's Head near Mount Rhodes, a hybrid swarm between both subspecies is found, where individual plants may have hairiness anywhere between that of both parents. Elsewhere, the populations are uniform and can easily be assigned to either of the subspecies. Differences with related species L. conocarpodendron differs from its nearest relatives by its tree-like habit, the narrowly cone-shaped common base of the flower heads, the oval involucral bracts with a pointy tip, and the broad cone-shaped pollen presenter. == Taxonomy ==

The earliest known description of the species we now know as Leucospermum conocarpodendron was by Paul Hermann in Paradisus Batavus, a book describing the plants of the Hortus Botanicus Leiden (botanical garden of the Leyden university), that was published in 1689, three years after his death. He called it Salix conophora Africana (African cone-bearing willow), based on his observation of Leucospermum conocarpodendron on the lower slopes of the Table Mountain. In the following six decades, several other descriptions were published, such as by Leonard Plukenet, James Petiver, John Ray and Herman Boerhaave. Names published before 1753, the year that was chosen as a starting point for the binominal nomenclature proposed by Carl Linnaeus, are not valid however. The tree pincushion was first validly described in the first edition of Species Plantarum as Leucadendron conocarpodendron by Linnaeus in 1753. Johann Jacob Reichard in 1779 reassigned the species to Protea, creating the new combination P. conocarpodendron. In 1781, Carl Peter Thunberg simplified the species name and created P. conocarpa, but because he used the same type as Linnaeus, he should have used the unchanged name. Richard Anthony Salisbury created two superfluous names, Protea tortuosa in 1796 and Leucadendrum crassicaule in 1809. In his book On the natural order of plants called Proteaceae that Robert Brown published in 1810, the species was reassigned to the new genus Leucospermum, but he combined it with Brown's invalid simplified species name to Leucospermum conocarpum. In 1874, Heinrich Wilhelm Buek made the correct combination Leucospermum conocarpodendron. Another form was described by Michael Gandoger in 1901, and he called it Leucospermum macowanii. In 1970, John Patrick Rourke proposed to distinguish between the typical subspecies (L. conocarpodendron subsp. conocarpodendron) and L. conocarpodendron subsp. viridum. The species and subspecies name conocarpodendron means "tree bearing cone-shaped fruits". The subspecies name viridum means "green" and is a reference to the leaves' colour. It was called kreupelhout in Dutch (cripple wood) already before 1680, a reference to the twisted branches that together give the tree a "crippled" appearance. == Distribution, habitat and ecology ==

L. conocarpodendron subsp. conocarpodendron is an endemic of the Cape Peninsula where it is limited to the eastern slopes of Devils Peak, the northern and western slopes of Table Mountain and the Black Table, to Llandudno. It grows mainly on heavy clay derived from the weathering of Cape Granite but also weathered Table Mountain Sandstone. It prefers north and west exposures that are well drained. == Conservation ==

Leucospermum conocarpodendron subsp. conocarpodendron is well protected in the Table Mountain National Park, where it is locally abundant. The subspecies is nonetheless regarded a vulnerable species as a significant part of its range was lost due to urbanization and land conversion to gum plantations and invasive plant species. Further housing developments of the Cape Town agglomerations could threaten remaining habitat. Alien ant species have driven back native ants. The alien ants eat the elaiosome on the spot, so that the seed is not protected against consumption or fire. Due to the proximity of housing areas, wildfires in its range are suppressed and so allow the fynbos to develop into a thicket less suitable for the grey tree pincushion, causing the fires when they eventually occur to be hotter because of more biomass, which results in more plants dying. Finally, subsp. viridum is planted in gardens within the range of subsp. conocarpodendron, which will lead to hybridization between the subspecies. This occurs even when the plants are quite far apart as both subspecies are bird pollinated. This could eventually lead to the extinction of subsp. conocarpodendron. In 2006, the seeds were successfully germinated by scientists at the Millennium Seed Bank in West Sussex, and were subsequently planted in the Temperate House at the Royal Botanic Gardens, Kew. == References ==