Portulaca is a genus that gives us a vegetable, a weed, and a flower. All flourish undaunted by heat or drought, a comforting thought as I drag the hose or lug a watering can around to keep beebalm, an Edelweiss grapevine, and some marigolds and zinnias — all planted within the last couple of weeks — alive.
Portulaca employ a special trick for dealing with hot, dry weather, which presents most plants with a conundrum. On the one hand, should a plant open the pores of its leaves to let water escape to cool the plant, as well as take in carbon dioxide which, along with sunlight, is needed for photosynthesis. On the other hand, the soil might not be sufficiently moist or the pores might end up jettisoning water faster than roots can drink it in, in which case closing the pores would be the ticket.
Portulaca gets around this …