These African natives are sedges grasslike plants distinguished from true grasses by three-angled, solid stems and very different flowering parts. Valued for striking form, silhouette, shadow pattern.
Most species grow in rich, moist soil or with roots submerged in water. Keep plants groomed by removing dead or broken stems; divide and replant when the clump becomes too large, saving smaller, outside divisions and discarding the overgrown centers. Beyond their hardiness range, pot up divisions and keep them over the winter as houseplants.
C. albostriatus. DWARF UMBRELLA PLANT. Zones LS, CS, TS; USDA 9-11. Resembles C. involucratus but tends to be less hardy and shorter (to 20 in.), with broader leaves and lusher, softer appearance. Vigorous, invasive plant; best used in contained space.
C. alternifolius. UMBRELLA PLANT. Zones CS, TS; USDA 9-11. Narrow, firm, spreading leaves arranged like ribs of umbrella at tops of 2- to 4-ft. stems. Flowers in dry, greenish brown clusters. Grows in water or moist soil. Effective near pools, in pots or planters, or in dry streambeds or small rock gardens. Self-sows. Can become weedy and take over a small pool. 'Nanus' ('Gracilis') is a dwarf form to 1 ft. high.
C. papyrus. PAPYRUS. Zones CS, TS; USDA 9-11. Tall, graceful, dark green stems 610 ft. high, topped with clusters of green, threadlike parts to 1 ft. long (longer than small leaves at base of cluster). Will grow quickly in 2 in. of water in shallow pool, or can be potted and placed on bricks or inverted pot in deeper water. Protect from strong wind. Also grows well in rich, moist soil out of water. Used by flower arrangers.
C. prolifer. DWARF PAPYRUS. Zones CS, TS; USDA 9-11. Flowers and long, thin leaves combine to make filmy brown-and-green clusters on slender stems about 1 ft. high. Use in Asian-style gardens; sink in pots in water gardens where delicate design of slender, leafless stems will not be lost among larger and coarser plants.