All plants need water to survive. However, like plants that require more water, there are plants that grow in a lack of water. They are the best drought tolerant plants and can live without water for a long time. - Flower Beds and Gardens
Foxglove (digitalis purpurea), an old-fashioned flower. Folk names include folk's gloves, as people used to think fairies used the flowers for gloves. Gorgeous in an early summer border. Grows well in Northern California
Parry's Penstemon- Penstemon parryi A species, and typical of Penstemon species plants, greyer and more woody, less floppy and much less tolerant of water than the garden hybrids usually called "Penstemon gloxinioides". These are plants for dry gardens.
Texas Sage (Leucophyllum frutescens) and all other Leucophyllum species have tiny hairs on their flowers, stems and their leaves, which help to deflect the sun's rays. It is these tiny hairs that give the leaves a gray-green color.