Identifying Powderpuffs - Sorocephalus
The genus Sorocephalus is easily recognized by its globose inflorescences, consisting of numerous heads (involucres) each consisting of 4-9 florets, subtended by inconspicuous bracts. The perianth is symmetrical, and fused for the lower half. The perianth is straight in the bud, short (8-25 mm), and styles are straight and filiform. Leaves are simple, small, either needle-like or with a groove on the upper surface. The fruit is a hairless nut with an lobed base.
The three main divisions into which the genus is divided are based largely on fruit morphology (which are difficult to find in the field) and leaf shape. Other features required for distinguishing species are the number of flowers in the inflorescences, the presence of hairs on the perianth limbs, the pollen presenter shape and the shape of the bracts.
1. Leaves flattened, with a flat or slightly curved upper surface goto 2
1' Leaves needlelike, canaliculate (with a canal-like groove) on the upper surface, fruit hairless, broadly lobed at base goto Section MISCHOCARYON
2. Fruit hairy, truncate at the base, small globose inflorescences containing only 4-5 four-flowered involucres, involucre bracts lanceolate goto Section DASYCARYON
2' Fruit hairless, narrowly lobed at base, inflorescences containing more than 10 four-flowered involucres, involucre bracts usually ovate goto Section SOROCEPHALUS
The Flat-leaf Powderpuffs are easy to discern from the Needle-leaf Powderpuffs, because their flat leaves are almost impossible to mistake for the slender needle-like leaves of the latter. The inflorescences contain more than 10 four-flowered involucres. The Flat-leaf Powderpuffs only occur north of Wellington-Worcester.
Sorocephalus scabridus TULBAGH POWDERPUFF
Sorocephalus lanatus COMMON POWDERPUFF
Sorocephalus capitatus WOOLLY
The Needle-leaf Powderpuffs all have long needle-like leaves, with a prominent canal on the upper leaf surface. The inflorescences consist of more than 30 flowers. The six species of Needle-leaf Powderpuffs are confined to the area south of Bainskloof and the Breede River
Important features in distinguishing the species include leaf length, number of flowers per involucre and inflorescence type.
Sorocephalus pinifolius LONG-LEAF POWDERPUFF Leaves 40-60 mm long, needle-shaped, long and slender, channelled on upper surface. Perianth limbs hairless. Pollen presenter ovoid.
Sorocephalus clavigerus ERECT POWDERPUFF
Sorocephalus palustris PROSTRATE POWDERPUFF
Sorocephalus crassifolius FLOWERLESS POWDERPUFF
Sorocephalus teretifolius PIN-SHAPED POWDERPUFF
The Diminutive Powderpuff is intermediate between Sorocephalus and Spatalla in that it has hairy fruit, a feature not found in other Powderpuffs. It also has the most diminutive of the inflorescences among the powderpuffs, containing only 16-20 flowers in the small inflorescence.