SANTALACEAE 161 



KEY TO THE GENERA. 



A. Calyx not produced into a tube above the ovary. Shrubs. 



a. Flowers bisexual. Leaves opposite. 



Endemic. Two species. (Plate 37.) 1. Colpoon Berg. 



(Syn. Rhoiacarpos) 



b. Flowers dioecious or polygamo-dioecious, the male flowers in 



terminal racemes. Leaves alternate. Semi-parasites. 



0. abyssinica (Transvaal sumach). 4 species in Trop. Afr. 



2. Osyris L. 



B. Calyx produced into a tube above the ovary. Shrublets with 



alternate, often scale-like leaves. 



a. Flowers bisexual; calyx 5-lobed. 



I. Fruit a drupaceous pseudocarp. 



1 S. A. species (O. natalensis). 4 in Trop. Afr. 



3. Osyridicarpos A. DC. 



II. Fruit nut-like, with a hard, dry shell. 



Semi-parasites, attached to the roots of various herbs and 



shrubs by means of haustoria. 

 About 70 S. A. species. (Plate 37.) 4. Thesium L. 



b. Flowers dioecious. Fruit embedded in a succulent coloured cup. 



Semi-parasites on the roots of shrubs. 



Endemic. 6 species. (Plate 37.) 5. Thesidium Sond. 



Plate 37. 

 Fam. 8. Santalaceae. 



A. Colpoon compression Berg. 1. Fruiting twig. 2. Flower. 3/1. 3. Flower, 

 long, section, showing the spiral columnar placenta in the centre, with three pendulous 

 ovules, each one curving upwards. 5. Insect from flower. (Class Cole?nbola.) 3/1. 



B. Thesidium fragile Sond. 1. Male twig. 2/1. 2. Female twig in flower. 2/1. 

 3. Fruiting plant. 



C. Thesium strictum Berg. 1. Young plant, parasitic on roots of Thamnochortus 

 dichotomus. 2. Flower. 3/1. 3. Ovary, long, section, showing the three pendulous 

 ovules, the spiral placentae artificially drawn out. 5/1. 



Fam. 9. Grubbiaceae. 



D. Grubbia stricta DC. Twig with flowers and fruits. 



E. Grubbia rosmarinifolia Berg., in flower. 



M. 21 



