Passerina is a genus of approximately 21 species of ericoid shrubs and shrublets in the family Thymelaeaceae, order Malvales. The genus is endemic to southern Africa, with the great majority of species confined to South Africa and the highest concentration in Cape fynbos.
Plants in the genus are small, heath-like woody shrubs, often with pendulous branches. Their leaves are markedly decussate — arranged in opposite pairs at right angles to those above and below — and are concave or tightly inrolled, lined with woolly hairs, and pressed close to the stem without covering it, creating a characteristic plaited or corded texture. Flowers are borne either in terminal spikes or in compact four-flowered heads; each flower is subtended by a bract that is broader and larger than the flower itself. There are no petals, but the four calyx lobes are often brightly coloured and petal-like. Eight stamens of unequal length protrude from the mouth of the calyx tube alongside a mop-like stigma. The absence of scent and the protruding stamens and stigmata indicate adaptation to wind pollination, distinguishing Passerina from the related genus Struthiola, which is insect-pollinated. In most species the fruit is dry and membranous, enclosed in the persistent calyx. In Passerina ericoides, however, the fruit is a fleshy red berry that protrudes from the calyx tube; it is attractive to birds and tortoises, and the Khoisan know it as "skilpadbessie" (tortoise berry).
The genus was first described by Linnaeus in Species Plantarum (1753). The Khoisan name gonna refers to the notably tough bark of Passerina and related plants, traditionally used for binding thatch and plaiting into whip thongs. Decoctions of certain species have been used medicinally for pain relief.
Etymology
The genus name Passerina derives from the Latin passer, meaning "sparrow," applied in reference to the perceived resemblance of the fruit to a sparrow's beak — an analogy particularly evident in Thymelaea hirsuta, a related plant formerly placed in Passerina. The same root gives the adjective passerinus, "sparrow-like."
Distribution
Passerina is endemic to southern Africa, with most species occurring within South Africa. The greatest concentration of species is in Cape fynbos, where several are restricted to very small areas; Passerina ericoides, for example, is found naturally only on the Cape Peninsula and in the vicinity of False Bay.
Ecology
Passerina species are wind-pollinated and are of limited importance to bees, birds, and other pollinators. The plants are generally unpalatable to browsing stock. Passerina ericoides produces fleshy red berries that are dispersed by birds and tortoises. The Khoisan name gonna refers to the tough, fibrous bark, which has been used for binding thatch and plaiting whip thongs; decoctions of some species have also been employed for pain relief, suggesting possible pharmacological activity within the family Thymelaeaceae.
Taxonomy Notes
Passerina was described by Linnaeus in Species Plantarum (559, 1753). The synonym genus Chymococca Meissn., also placed in Thymelaeaceae, has been subsumed into Passerina. GBIF places the genus in order Malvales, class Magnoliopsida. The bird genus Passerina (family Cardinalidae) is an entirely unrelated homonym introduced by Vieillot in 1816.
