KEY TO THE GENERA
EMBRYOPHYTA SIPHONOGAMA
(PHANEROGAMAE)
SUBDIVISION GYMNOSPERMAE
CLASS I. CYCADALES
[FAMILY 1.] CYCADACEAE
Stem simple, rarely branched at the top, woody, with mucilagineous juice. Leaves pinnate or pinnatisect, forming a tuft at the top of the stem and intermingled with scales. Flowers solitary, terminal, in the shape of a cone (but sometimes overtopped by the continued growth of the stem), dioecious, without a perianth. Stamens bearing many pollen-sacs on their lower side. Ovules 2-8 to each carpel, straight, with a single coat. Seeds drupe-like, albuminous. Embryo with two more or less united cotyledons.—Genera 3, species 25. Tropical and South Africa. (Plate 1.)
1. Stem growing through the female flower, covered with the remains of the old leaves. Leaf-segments one-nerved, coiled in bud. Carpels pinnately toothed or cleft, each with 4-8 ascending ovules.—Species 2, one growing wild in Madagascar and the neighbouring islands, the other cultivated and sometimes naturalized in various parts of Africa. Used as ornamental and medicinal plants; the fruits are edible and the pith contains starch (sago). [Tribe CYCADEAE.] Cycas L.
Stem not growing through the female flower. Leaf-segments with several nerves, straight in bud. Carpels each with 2 descending ovules. [Tribe
ZAMIEAE.] 2
2. Leaf-segments with pinnate nerves. Stem without remains of old leaves at the base. Cone-scales (stamens and carpels) imbricate.—Species 2.
South-east Africa (Natal). Used as ornamental plants. Stangeria Th. Moore
Leaf-segments with parallel nerves. Stem covered with the remains of old leaves. Cone-scales not imbricate.—Species 20. South and Central
Africa. The pith (Kaffir-bread) and the seeds of some species are eaten and also used for making a sort of beer. Several species yield gum or serve as ornamental plants. (Plate 1.) Encephalartos Lehm.
CLASS II. CONIFERAE
[FAMILY 2.] TAXACEAE