These families contain very primitive plants, frequently referred to as ‘living fossils’ and collectively known as cycads. The indigenous cycads of this country belong to two genera of Zamiaceae, viz. Stangeria, a stemless, fern-like genus, restricted to forests of Natal and the Eastern Cape, and Encephalartos 59, which includes all the cultivated species that are considered to be among the choicest of garden subjects. Both genera are totally protected and may not be collected in the wild.Several exotic cycads, belonging to the family Cycadaceae are also cultivated in this country, particularly in the genus Cycas. Read the rest of this entry »

Fern with a branching, creeping underground stem and fronds up to about 1 m high, dying down in winter. Usually 3 main fronds per stem. Leaf roughly triangular in outline, divided into leaflets which are again divided into lobed leaflets and these are sometimes even divided again into leaflets. Bracken grows in, or on the edge of forests and also on dry open ground. It is poisonous and stock losses have occurred. The chief toxic principle is the enzyme, thiaminase, which destroys vitamin B in the animal’s gut, but other noxious substances such as a cyanogenic glycoside and carcinogens also occur.

Plants with underground rootstocks and harsh, ribbed stems up to 1 m high. Branches in circlets around stems, with small, tooth-like leaves. No flowers, but small, oval reproductive bodies (strobili) are produced at the tips of fertile stems. Horsetails grow mainly in, or near water. They are poisonous and have caused stock losses. The poisonous principle is an enzyme, thiaminase, which destroys vitamin B (thiamine) in the alimentary tract of the animal.