288 Plants and their Ways in South Africa 



Leaves entire, small ; heads small . Diastella. 

 Leaves large, expanded ; heads large 

 with large showy bracts . . Orothamnus. 

 Flowers in i-flowered or 2-6-flowered invol- 

 ucred heads, clustered in spikes or 

 heads. 

 Calyx regular. 



Achene not stalked; upper leaves 



entire or cut, lower pinnati parted Nivenia. 

 Achene stalked ; leaves linear entire, 



or some of the lower compound Sorocephalus. 

 Calyx irregular, 1 sepal larger . . Spatalia. 

 Flowers in spikes or racemes (not in heads) 

 Anthers sessile; nut bearded; spikes 

 terminal ; leaves alternate, not 



notched Faurea. 



Anthers on short filaments ; ovules 2 ; 

 drupe velvety ; racemes axillary ; 

 leaves whorled, serrate ; fls. perfect 

 and imperfect .... Brabeium. 



According to Dr. Wiegand, hairy coverings are employed by plants 

 in situations where, as on Table Mountain, a supply of water is available 

 but where there is bright sunshine and frequent high winds. Hairs do 

 not interfere with transpiration when mists hover over the mountain. 



Cutin, on the other hand, is effective in places where a scarcity of 

 water is constant. 



Leucadendron. — Flowers dioecious, borne in cone-like 

 heads. Involucre formed by the upper leaves, which give the 

 delicate yellow colour to the veld in spring where these shrubs 

 abound. In some species the involucre is reddish. The fruit 

 may be flat, and distributed by wings or globose, as in the 

 Silver Tree (Z. argenteum, R. Br.) (see pp. 155, 188). About 

 sixty species chiefly in the Coast region. 



Protea flowers are perfect ; one perianth segment be- 

 comes separated from the other three. The genus may be 

 distinguished by this character and by the showy involucres. 

 The style remains on the hairy ovary. The involucres of P. 

 mellifera^ Thunb. (the Sugar Bush) are often half filled with 

 honey in the early morning. The firm involucres in some 

 species serve as a landing place for birds which aid in pollina^ 

 tion. 



