Africa Aizoaceae botanical botany bright clear common costal crystalline crystallinum diamond dots dry fig fleshy hot Iceplant icicle icy leaf Mesembryanthemum plant reservoir shimmering silver south succulent summer sun thick warm angular-pigface Cape-fig carpobrotus-glaucescens coastal creeping-succulent daisy-like-flowers drought-resistant dune-stabilizer edible fire-resistant flora flower flowers food groundcover Hottentot-plant ice-plant invasive medicinal nutritional open perennials pigface pink-purple plant-mat prostrate salt-substitute salt-tolerant sand-dunes sand-stabilizer smooth-leaves sour-fig strand-ivy sunlight sunshine triangular-leaves yellow bee bees insect insects