Leucospermum hypophyllocarpodendron is a creeping, mat-forming shrub with heads of yellow flowers and leathery, upright narrow leaves with some red-tipped teeth at their tips, from the family Proteaceae. It has long thin branches that originate from an underground rootstock and grows on poor, sandy soils in southwestern South Africa. The rose-scented flower heads can be found for August to January and are visited by different monkey beetles, bees and flies. It has two subspecies, one with greyish leaves U-shaped in cross section called grey snakestem pincushion in English and gruisslangbossie in Afrikaans, the other with green leaves that are flat in cross-section called green snakestem pincushion and groenslangbossie.
Description
Leucospermum hypophyllocarpodendron is a prostrate shrub (rarely rising up) of no more than high, with branches that spread out over the ground and form mats of ½–1½ m (1⅔–5 ft) in diameter. The branches originate from an underground rootstock. When the branches flower, they are in diameter and initially covered in fine grey crisped hairs, which wear off with age. Its leaves are upright, linear and U-shaped in cross section in one subspecies, narrowly lance-shaped with a narrow wedge-shaped foot in the other, long and up to 1½ cm (0.6 in) wide, and mostly with two to four thickened teeth that are tinged red, in one subspecies initially with soft, grey, crisped hairs, which may partially wear off when aging, or almost hairless and bright green from the start in the other.
The flower heads occur in groups of up to four together mostly at a right angle to the branch, each on a long stalk, are somewhat flattened globular in shape, and in diameter, arising in groups of up to 4, generally upright. The common base of the flowers in the same head is cone-shaped with a pointy tip, 1½ cm (0.6 in) high and ¾–1 cm (0.3–0.4 in) wide. The bracts are very broad oval in shape with a pointy tip long and wide, with or without some soft hairs, rubbery, overlapping and pressed against the underside of the flower head. The bracts that support each flower individually (called bracteoles) is rubbery, thickly woolly at the base and hairy higher up, wraps around the base of the flower, is oval with a pointy tip, about long and mm wide. The bright yellow perianth is long, tube-shaped, in the bud slightly bent towards the center of the flower head. The fused tube at the base is about long with very fine soft hair but hairless facing the center of the flower head. The three perianth lobes facing the center of the head together form a hairless sheath while the lobe facing the rim of the head is free, the sheath and free lobe strongly rolled when the flower has opened. The yellow style is slim, straight or a little bit bent towards the center of the head and long. The thickened part at the tip called pollen presenter is slightly split in two at the top, 1½–2 mm (0.06–0.08 in) long, with the grove that functions as the stigma at the very tip. The ovary is subtended by four narrow awl-shaped scales of long, or may be absent. The flowers of Leucospermum hypophyllocarpodendron are sweetly scented.
The subtribe Proteinae, to which the genus Leucospermum has been assigned, consistently has a basic chromosome number of twelve (2n=24).
Subspecies
The snakestem pincushion has two subspecies.
Differences with other species
Although L. hypophyllocarpodendron is not closely related, it can easily be mistaken for L. prostratum that is also a trailing shrub with upright leaves and small yellow flower heads, but that species has entire, flat, lance-shaped leaves, and all four perianth lobes are free and roll back on themselves. L. hypophyllocarpodendron differs from its relatives of the section Leucospermum because it is the only one with a prostrate habit with trailing branches, with up-right leaves, sometimes U-shaped in cross-section, and broad involucral bracts.