Giant Rosette Plants

Acaulescent Plants

The most typical life form of alpine tropical regions are the giant-rosette plants of the genera Lobelia (Lobeliaceae) and Senecio (Asteraceae) in Africa, Espele-tia (Asteraceae) in South America and Argyroxiphium (Asteraceae) in Hawai'i (Fig. 12.5). They may reach heights of several meters and have developed a number of morphological and anatomical features adapting them to the diurnal type of climate in their habitat. The tallest plant of Senecio johnstonii ssp. cottonii actually measured by...

Thorn Scrub and Cactus Forests

Venezuela Forest

Examples comparing the physiognomy of a thorn scrub and a cactus forests are shown in Figs. 3.10 and 3.11. The term cactus forest was coined by Vareschi 1980 . Cactus-forests represent an example of thornbush-succulent forests. This type of forest in Madagascar covers a small area in the south-west of the island see Fig. 2.14 dominated by Didieraceae 11 species in 4 genera , Euphorbiaceae and other succulent and deciduous woody species Fig. 3.12 . It is also characteristic of the Caatinga...