| Bergerocactus | |
|---|---|
 | |
Scientific classification | |
| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Angiosperms |
| Clade: | Eudicots |
| Order: | Caryophyllales |
| Family: | Cactaceae |
| Subfamily: | Cactoideae |
| Tribe: | Echinocereeae |
| Genus: | Bergerocactus Britton &Rose |
| Species: | B. emoryi |
| Binomial name | |
| Bergerocactus emoryi | |
| Synonyms[3] | |
| |
Bergerocactus emoryi is aspecies ofcactus, known commonly as thegolden-spined cereus,golden snake cactus,velvet cactus orgolden club cactus. It is a relatively small cactus, but it can form dense thickets or colonies, with the dense yellow spines giving off a velvety appearance when backlit by the sun. From April to May, yellow, green-tinged flowers emerge, which transform into reddish, globular fruit. This species is native to theCalifornia Floristic Province, and is found in northwesternBaja California and a small part ofCalifornia, inSan Diego County and on the southernChannel Islands. Where theMediterranean climate of the California Floristic Province collides with the subtropicalSonoran Desert nearEl Rosario, hybrids with two other species of cacti are found. It is the sole member of the monotypicgenusBergerocactus, named after German botanistAlwin Berger.[4][5]
This species is ashrub-like cactus, formingthickets of columnar toprostrate stems. The colonies have a velvety appearance when backlit by the sun. The stems are usually less than 2 metres (6.6 ft) long, covered in numerous, interlaced, yellow and needle-likespines. The stems are 3–6 cm (1.2–2.4 in) in diameter, cylindrical, and with 12 to 18 ribs. There are 30 to 45 spines perareole, and most are less than 2 mm (0.079 in) in diameter. There are 1 to 3 central spines, which are curved downward, the longest less than 6 cm (2.4 in). The radial spines are straight.[5][6]
Theflowers emerge either laterally or at the apex of the stem, at the distal margin of the spine cluster. The flower is 3.5–5 cm (1.4–2.0 in) long, and 2.5–4 cm (0.98–1.57 in) in diameter. Theovary is free of hair, and densely spiny. The outerperianth parts are yellow, with the tips more-or-less red, and the midveins green, with all of the inner perianth colored yellow. After blooming, a reddish, globularfruit emerges, covered in dense spines, and extruding seeds and pulp at the tip. The seeds are 3 mm (0.12 in) large, shiny and black.[5][6]
The cactus has a chromosome count of 2n=44.[6] There is an extensive number of common names, which include the golden cereus, golden-spined cereus, golden snake cactus, velvet cactus, golden club cactus. The plant is also known as snake cactus, though this latter name also applies toEchinocereus pensilis.
The golden cereus is known tohybridize with other species of cacti. Both occur in the vicinity ofEl Rosario. Hybrids include:
Moran (Lindsay hybrid cactus)
A naturally occurring intergeneric hybrid withMyrtillocactus cochal.[4] It is atriploid plant, which helps substantiate that it is a hybrid between the diploidM. cochal and the tetraploidB. emoryi. It has light-yellow flowers, and is known only from a few plants.[5] Itsgeneric name comes from those of its parents (Mytillocactus andBergerocactus) and itsspecific epithet,"lindsayi", is in honor of the botanistGeorge Lindsay. The cactus was first found by Lindsay nearEl Rosario, Baja California, in 1950 while on a trip to look forPacherocactus. Specimens were cultivated at theDesert Botanical Garden, finally blooming in 1961 and formally described the following year.[7]
(K. Brandegee) G.D. Rowley (Orcutt hybrid cactus)
A naturally occurring intergeneric hybrid withPachycereus pringlei,[4] discovered nearEl Rosario, Baja California. The plant's generic name is formed from those of its parents (Pachycereus andBergerocactus). Sometimes it can be found listed asPachycereus ×Bergerocactus.[8] It can grow to a height of about 3.5 m and a diameter of about 10 cm. The cactus does not thrive below 10 °C. Its flowers are green-brown in color and of about 4 cm in size.[9]
The plant is near-endemic toBaja California, with the exception of populations onSanta Catalina Island,San Clemente Island, andSan Diego, California. The populations remaining in San Diego are disjunct, located inBorder Field State Park,Torrey Pines State Park, andCabrillo National Monument, as the urban development in San Diego has relegated many species to these protected areas.[10]
Other rare species that inhabit these enclaves ofmaritime succulent scrub in San Diego includeShaw's Agave, theTorrey Pine, theTapertip liveforever,cliff spurge, and theSan Diego barrel cactus.[11] Aside from urban development, the plant is also threatened by collecting and feral goats.[6]
The species is represented on the two of the southernCalifornia Channel Islands. On San Clemente Island, the golden cactus is found inhabiting rocky canyon walls.[12]
In Baja California, the species continues from the border south into the succulent scrub toEl Rosario.[4] It occurs on numerous islands off the coast; however,climate change and other anthropogenic influences are threatening the insular populations. OnIsla San Martin, avolcanic island off of theSan Quintin Bay, only a single clump of the cactus is left.[13]
Flora of the maritime succulent scrub:
