old man cactus
Cephalocereus senilis
Summary 7
Cephalocereus senilis (old man cactus) is a species of cactus native to Guanajuato and Hidalgo in eastern Mexico. It is threatened in the wild, but widespread propagation and popularity in cultivation have reduced the demand on wild populations.
Description 8
Cephalocereus senilis is a tall, columnar species with clusters of stems that may grow to 5–15 m tall; the individual stems are usually unbranched, being unable to withstand the weight of side branches adequately. The most striking feature is the shaggy coat of long, white hairs suggestive of unkempt hair on an old man. The coat is a particularly striking silvery white on the young cactus; as the plant ages the stem begins to lose its covering. The flowers are red, yellow, or white, though the plant may not flower until 10–20 years old.
Cultivation 8
Cephalocereus senilis is a very popular cactus in cultivation, grown for its woolly appearance. It prefers a very well-drained soil mix (more so than many other cacti), and much bright sunlight, which encourages growth of the hair.
Morphology and function of the coat 8
The hairs are modified spines and they make many a plant appear almost snow-white; they serve to protect the plant from frost and sun. However, the hairs are only the radial spines of the cactus; they conceal formidable sharp yellow central spines that belie the inoffensive appearance of the hairy covering.
Sources and Credits
- (c) Pedro Nájera Quezada, some rights reserved (CC BY-NC), uploaded by Pedro Nájera Quezada
- (c) gcosultchi, some rights reserved (CC BY-NC), uploaded by gcosultchi
- (c) Eva Uribe, some rights reserved (CC BY-NC), uploaded by Eva Uribe
- (c) Carlos G Velazco-Macias, some rights reserved (CC BY-NC), uploaded by Carlos G Velazco-Macias
- (c) Opuntia Cadereytensis, some rights reserved (CC BY-NC), uploaded by Opuntia Cadereytensis
- (c) Reserva de la Biosfera Barranca de Metztitlán (RBBM), some rights reserved (CC BY-NC), uploaded by Reserva de la Biosfera Barranca de Metztitlán (RBBM)
- Adapted by Jeny Davis from a work by (c) Wikipedia, some rights reserved (CC BY-SA), https://en.wikipedia.org/wiki/Cephalocereus_senilis
- (c) Wikipedia, some rights reserved (CC BY-SA), https://en.wikipedia.org/wiki/Cephalocereus_senilis
More Info
- iNat taxon page
- Biodiversity Heritage Library
- BOLD Systems BIN search
- eFloras.org
- Flora of North America (beta)
- Global Biodiversity Information Facility (GBIF)
- HOSTS - a Database of the World's Lepidopteran Hostplants
- IPNI (with links to POWO, WFO, and BHL)
- NatureServe Explorer 2.0
- Plants of the World Online
- SEINet Symbiota portals
- Tropicos
- World Flora Online
