Among these odd species are the welwitschia (Welwitschia mirabilis, see box), a strange gymnosperm with indefinitely growing leaves that is a genuine living fossil, and the shrub Myrothamnus flabellifolius, the only mainland African species of its genus and of he family Myrothamnaceae--it contains only one other species, from the arid regions of Madagascar--which
estivates (becomes dormant in the summer) by drying its leaves out, folding them like a fan, and turning black and brittle.