groundsel
- Also called:
- ragwort
groundsel, (genus Senecio), large genus of about 1,200 species of flowering plants in the aster family (Asteraceae) distributed throughout the world. Some species are cultivated as border plants or houseplants, and many species contain alkaloids that are poisonous to grazing animals.
Physical description
A diverse group, groundsels can be annual, biennial, or perennial herbs, shrubs, trees, or climbers. Some species are succulents. Members of the genus have flower heads that usually are composed of yellow disk and ray flowers. Bracts (leaflike structures) are located below the flower heads.
Major species
Common groundsel (Senecio vulgaris) is an annual herb native to northern Africa and Europe; it has yellow daisylike flowers. Ragwort, or tansy ragwort (S. jacobaea); cineraria, or dusty miller (S. cineraria); and golden ragwort (S. aureus) are cultivated as border plants. German ivy (S. mikanoides) and florist’s cineraria (S. cruentus) are popular houseplants.
Blue chalk stick, or blue ice plant (S. serpens), is frequently grown as a succulent ground cover or in rock gardens. The South African cocoon plant (S. haworthii) has unusual succulent cylindrical leaves that resemble insect cocoons. Spear head (S. kleiniiformis) gets its name from its triangular green leaves. String of bananas (S. radicans) and string of beads (S. rowleyanus) are both South African vine succulents and are frequently grown as hanging potted plants. Vertical leaf senecio, or propeller plant (S. crassissimus), features dramatic blue leaves with purple margins and is a popular houseplant. Woolly senecio (S. scaposus) is a pubescent succulent with silver finger-shaped leaves.
Some botanists now prefer to divide this large and diverse genus into different segregated genera. A number of succulent species are placed in the genus Curio by some authorities.