Serruria rubricaulis is an attractive curly spiderhead shrublet reaching heights to about 30 cm. The plant resprouts after fire from its underground rootstock, unlike S. adscendens, a similar-looking, but reseeder species.
The stems of S. rubricaulis are markedly reddish. The specific name, rubricaulis, is derived from the Latin words ruber meaning to be red or ruddy and caulis meaning the stem of a plant, referring to the stem colour.
Like Serruria plants generally, the leaves are divided into feathery, erect, cylindrical segments. In S. rubricaulis there are about 12 to 18 segments to a leaf.
Several of the Serruria species, including S. rubricaulis, have flowers without bracts, positioned among the leaves at branch tips.
The whitish pink and woolly, bisexual florets making up the mop-head appearance start off as dense clusters of curved buds. The blooming season is late winter and spring. The florets are pollinated by insects.
The fruits are released about two months after flowering. Seeds are distributed by ants that carry them off and eat the fleshy, non-vital parts, grown for their benefit and dispersal service.
The species distribution is limited, in the far southwest of the Western Cape from the Hottentots Holland Mountains to the Kleinrivier Mountains near Hermanus and Stanford.
The habitat is sandstone and ferricrete fynbos mountain slopes. The species is considered near threatened in habitat early in the twenty first century, due to habitat loss from urban expansion and alien vegetation invasion (Bean and Johns, 2005; iNaturalist; www.fernkloof.com; www.protea.worldonline.co.za; http://redlist.sanbi.org).