Dudleya
Dudleya | |
---|---|
Short-leaved dudleya (Dudleya brevifolia) at Carmel Mountain, San Diego | |
Scientific classification ![]() | |
Kingdom: | Plantae |
Clade: | Tracheophytes |
Clade: | Angiosperms |
Clade: | Eudicots |
Order: | Saxifragales |
Family: | Crassulaceae |
Subfamily: | Sempervivoideae |
Tribe: | |
Genus: | Dudleya Britton & Rose |
Species | |
Numerous, see text |
![](http://upload.wikimedia.org/wikipedia/commons/thumb/6/6a/J20160421-0064%E2%80%94Dudleya_cymosa%E2%80%94RPBG_%2826624941195%29.jpg/220px-J20160421-0064%E2%80%94Dudleya_cymosa%E2%80%94RPBG_%2826624941195%29.jpg)
Dudleya is a genus of succulent perennial plants, consisting of about 46 species with around 68 taxa in southwestern North America. Dudleya are fleshy, glabrous plants, sometimes farinose, with leaves that are typically organized into rosettes. The flowers of Dudleya typically have petals and sepals numbered in 5, and when fruiting are filled with tiny, ovoid or crescent-shaped seeds. Some species are cultivated as ornamental plants, and others are threatened by poaching.[1]
Description[]
The fleshy and glabrous leaves occur in rosettes, in colors generally ranging from green to gray, with some species having their foliage covered in an epicuticular wax, or farina.[1]The farina is mostly composed of pentacyclic triterpenoids.[2] Other members, such as D. viscida and D. anomala, have a viscid, adhesive layer on their foliage. The inflorescences are on vertical or inclined stems up to a meter high, but usually much shorter, topped by a cyme with alternate leaf-like bracts. Both the petals and sepals of the small flowers are five in number and fused below. Five pistils, also fused below, have 10 stamens arranged around them.
Etymology[]
The genus is named after William Russell Dudley, the first head of the botany department at Stanford University. Members of the genus are commonly referred to as liveforevers.[1]
Taxonomy[]
Many plants in the Dudleya genus were formerly classified as Echeveria.
Taxonomic classification of Dudleya taxa remains problematic, as members of the genus freely hybridize with each other and often occur in difficult locations for observation.
Cladogram of resolved Dudleya species[3] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Members of the former subgenus Hasseanthus are shaded blue, and members of the former subgenus Stylophyllum in red.
Species not listed are unresolved. |
Selected species[]
![](http://upload.wikimedia.org/wikipedia/commons/thumb/9/9d/Dudleya_gnoma.jpg/200px-Dudleya_gnoma.jpg)
- Dudleya abramsii – Abrams' live-forever
- Dudleya abramsii subsp. parva – Conejo dudleya
- Dudleya abramsii subsp. setchellii – Santa Clara Valley dudleya
- – Vizcaino live-forever[4]
- – White-flower live-forever[4]
- Dudleya anomala – Todos Santos live-forever[5]
- Dudleya anthonyi – Anthony's live-forever. Formerly in Echeveria
- Dudleya attenuata – Orcutt's live-forever, tapertip live-forever. Formerly in Echeveria, sometimes included in D. edulis
- Dudleya arizonica – Arizona chalk dudleya. Formerly a subspecies of Dudleya pulverulenta. Syn. D. lagunensis. [6]
- Dudleya blochmaniae – Blochman's live-forever, Blochman's dudleya
- Dudleya brevifolia – Short-leaved live-forever, short-leaved dudleya. Formerly a subspecies of D. blochmaniae
- Dudleya brittonii – Britton's dudleya, giant chalk dudleya
- Dudleya caespitosa – Sea lettuce. Syn. Dudleya lingula, Echeveria californica, E. cotyledon, E. helleri, E. laxa, Sedum cotyledon.
- Dudleya calcicola – Limestone dudleya
- Dudleya campanulata – Punta Banda live-forever[7]
- Dudleya candelabrum – Candleholder live-forever
- Dudleya candida – Coronados live-forever. Syn. Echeveria candida, Dudleya bryceae.[8]
- – Thick-leaf dudleya[9]
- Dudleya cultrata – Knife-leaved live-forever, maritime succulent live-forever. Formerly in Echeveria[4]
- Dudleya cymosa – Canyon live-forever. Syn. Dudleya sheldonii, Echeveria laxa var. cymosa. [10]
- Dudleya densiflora – San Gabriel Mountains live-forever
- Dudleya edulis – Fingertips. Formerly in Echeveria or Sedum.
- Dudleya farinosa – Bluff lettuce, powdery live-forever, powdery dudleya. Syn. Dudleya compacta
- Dudleya formosa – La Mision live-forever[11]
- Dudleya gatesii – Gates live-forever [12]
- Dudleya gnoma – Munchkin dudleya. Syn. Dudleya nana
- Dudleya greenei – Greene's dudleya. Syn. Dudleya hoffmannii, D. regalis [12]
- Dudleya guadalupensis – Guadalupe live-forever
- Dudleya ingens – Baja live-forever, rock live-forever[13]
- Dudleya hendrixii – Hendrix's live-forever[14]
- Dudleya lanceolata – Lanceleaf live-forever.
- Dudleya linearis – San Benito Island live-forever
- Dudleya multicaulis – Many-stemmed dudleya
- – Cape live-forever. Syn. Cotyledon nubigena, Echeveria nubigena, Dudleya xanti.[15]
- Dudleya nesiotica – Santa Cruz Island live-forever
- Dudleya pachyphytum – Cedros Island dudleya[16]
- Dudleya palmeri – Palmer's live-forever
- Dudleya pauciflora– Few-flower live-forever[4]
- Dudleya pulverulenta – Chalk lettuce, chalk dudleya, chalk live-forever. Syn. Echeveria argentea, E. pulverulenta, Cotyledon pulverulenta.
- Dudleya rigida – Sierra de la Laguna live-forever[4] [17]
- – Playa Maria live-forever[4]
- Dudleya rubens – Red flowering live-forever[4]
- Dudleya saxosa – Panamint live-forever
- Dudleya saxosa subsp. collomiae – Gila County live-forever. Syn. Echeveria collomiae.
- Dudleya stolonifera – Laguna Beach live-forever
- Dudleya traskiae – Santa Barbara Island live-forever
- Dudleya variegata – Variegated live-forever
- Dudleya verityi – Verity's live-forever
- Dudleya virens – Alabaster plant, Island live-forever. Syn. Dudleya chilensis, D. matsonii.[18][19]
- Dudleya viridicata – Colonet live-forever
- Dudleya viridis
- Dudleya viscida – Sticky dudleya
Distribution and habitat[]
Dudleya species are widespread in their range, typically found in rock outcroppings, cliff faces, or road cuts, where their leaves help them store water in a setting too dry for most types of plants. Most are small and inconspicuous when not in bloom.
Dudleya can be found in The Californias, Arizona, Sonora, Oregon and southern Utah and Nevada. A large portion of Dudleya taxa exist in coastal regions, although some can be found over vast swathes of the interior of Southwestern North America.[20]
Species existing in the Baja California peninsula, particularly D. rigida, D. pauciflora and D. nubigena, occur in high altitude, montane regions. [17]
Cultivation[]
In horticulture, Dudleya should be planted at an angle. This allows accumulated water to drain from the nestlike center of the plant, thus preventing microbial decay. Dudleya should not be watered from directly above, as this may damage their chalky coating known as farina, which is present on numerous species. Mealybugs and aphids are main pests of Dudleya.[21][22] Powdery mildew has also been recorded in cultivated Dudleya.[23]
Propagation[]
Unlike their related genera Echeveria, Dudleya cannot be propagated through leaf cuttings. Propagation can only be achieved via offsets or germination by seed. Dudleya seeds are crescent shaped and near-microscopic, and can be collected by taking the dried flower buds and crushing the ovules inside, which can contain hundreds of seeds. Seeds can be sown into a soilless medium, such as pumice or vermiculite, after which germination can occur within a week to 10 days.[24]
Conservation[]
Several species of Dudleya are threatened by urban development in Coastal California and Mexico, and anthropogenic-induced wildfires. However, one of the most critical threats to Dudleya species is poaching, partially caused by a demand from East Asian succulent collectors paying lucrative prices for certain Dudleya species.[25]
The population of Verity's live-forever, which was nearly wiped out during the 2013 Springs Fire, was targeted by poachers.[26][27]
The Cedros Island Dudleya, D. pachyphytum, a rare and extremely specialized Dudleya endemic to Cedros Island, was nearly extirpated after Mexican soldiers stopped poachers from taking nearly 5,000 rosettes in a tractor-trailer. It was suspected the poachers rappelled onto the succulent's location via helicopter, as D.pachyphytum occupies a nearly inaccessible habitat. In 2019, the deaths and injuries of several fishermen from Bahía Tortugas on Cedros Island was allegedly the result of Dudleya trafficking, a conflict with the Sinaloa Cartel, or both. In 2020, the Mexican Navy in the Second Naval Region reported that two fishermen were killed after a dispute emerged over the trafficking of the rare plant.[28][29][30][31][32]
Bluff lettuce (D. farinosa) was also targeted by poachers in numerous large-scale operations. Although not particularly rare, the size of the poaching operation pose a serious ecological threat. Starting in 2017, the U.S. Customs and Border Protection, along with the California Department of Fish and Wildlife, discovered large amounts of D. farinosa being shipped out of the country. South Korean and Chinese nationals have both been arrested in the smuggling of D. farinosa. According to nursery owners responsible for legally exporting Dudleya, buyers in Asia desired plants directly from the wild, owing to the aesthetic quality of their long caudices and weathered leaves.[33][34]
In response to the poaching of Dudleya, California State Assembly member Chris Ward proposed Bill AB-223, which would make it illegal to poach Dudleya.[35]The California Native Plant Society and conservationists have also initiated propagation programs to oversaturate the market as a means to deter poachers.[24][36]
References[]
- ^ Jump up to: a b c McCabe, Stephen Ward. "Dudleya, in Jepson eFlora". Jepson Flora Project (eds.). Jepson Herbarium. Retrieved 8 June 2020.
- ^ Manheim Jr, B. S., & Mulroy, T. W. (1978). Triterpenoids in epicuticular waxes of Dudleya species. Phytochemistry, 17(10), 1799-1800.
- ^ Yost, J. M.; Bontrager, M.; McCabe, S. W.; Burton, D.; Simpson, M. G.; Kay, K. M.; Ritter, M. (2013). "Phylogenetic relationships and evolution in Dudleya (Crassulaceae)" (PDF). Systematic Botany. 38(4): 1096–1104.
- ^ Jump up to: a b c d e f g Britton ex Britton & Rose, 1903 In: Bull. N. York Bot. Gard. 3
- ^ Moran, 1943 In: Desert Pl. Life 14: 191
- ^ Walther. In: Leafl. West. Bot. 1: 29. (1932)
- ^ Moran, R. (1978). Dudleya campanulata, a new species from Baja California. Cactus and Succulent Journal.
- ^ "Dudleya bryceae". GBIF.
- ^ Dodero, M. W. and M. G. Simpson. (2012). "Dudleya crassifolia (Crassulaceae), a new species from northern Baja California, Mexico". Madroño 59(4) 223–229.
- ^ "Dudleya cymosa". SEINet.
- ^ Moran, 1950 In: Desert Pl. Life, 22: 65
- ^ Jump up to: a b D. A. Johans. In: Cact. & Succ. Journ. Amer. 4. (1932)
- ^ D. A. Johans. In: Cact. & Succ. Journ. Amer. 6: 122. (1935)
- ^ Said to have been published in the December 2016 issue of Madroño.
- ^ "Dudleya xanti". World Flora Online.
- ^ R. Moran & M. Benedict, 1980 In: Phytologia, 47(2): 85
- ^ Jump up to: a b Moran, Reid. "Dudleya rigida" Cactus and Succulent Journal of America
- ^ "Dudleya chilensis". GBIF.
- ^ "Dudleya matsonii". GBIF.
- ^ Thiede, J. (2004). The genus Dudleya Britton & Rose (Crassulaceae): its systematics and biology. Cactus and Succulent Journal (US), 76, 224-231.
- ^ Hodgkiss, R.J. (5 February 2021). "Dudleya - Crassulaceae". The Succulent Plant Page.
- ^ Bornstein, Carol; Fross, David; O'Brien, Bart (2005). California Native Plants for the Garden. Los Olivos, California: Cachuma Press. ISBN 0-9628505-8-6.
- ^ Henricot, B. (2008). Occurrence of powdery mildew (Erysiphe sp.) on Echeveria spp., Crassula spp., Cotyledon and Dudleya in the UK. Plant Pathology, 57(4).
- ^ Jump up to: a b Chesnut, John (October 2018). "Defeat Dudleya Poaching Through Propagation". CNPS-SLO. California Native Plant Society.
- ^ Margulies, J. D. (2020). Korean ‘Housewives’ and ‘Hipsters’ Are Not Driving a New Illicit Plant Trade: Complicating Consumer Motivations Behind an Emergent Wildlife Trade in Dudleya farinosa. Frontiers in Ecology and Evolution, 8, 367.
- ^ Carlson, Cheri (April 18, 2019). "First a wildfire, then poachers. How a rare Ventura County plant has been nearly wiped out". Ventura County Star. August 16, 2021.
- ^ Townsend, Peggy (25 April 2019). "Succulent savior". UC Santa Cruz Newscenter. University of California, Santa Cruz.
- ^ "Reconoce Marina extracción y tráfico de "siempre viva" en Isla de Cedros". Investigaciones Zeta. 20 January 2021. Retrieved 21 August 2021.
- ^ Uhler, M. (2018). At the edge of California and the edge of existence: How siemprevive de Isla de Cedros (Dudleya pachyphytum [Crassulaceae]) was poached ever closer to extinction. CNPS 2018 Conservation Conference: Horticulture as a Part of Conservation. California Native Plant Society
- ^ "Militares decomisan plantas endemicas". MAS Noticias BCS. 28 May 2017.
- ^ McCabe, S.W. (September 24, 2019)
- ^ "CJNG en desaparición de pescadores". Investigaciones Zeta. 9 December 2019. Retrieved 21 August 2021.
- ^ Callahan, Mary (9 March 2019). "Plant smugglers take 'massive toll' on California's Dudleya farinosa succulent species". The Press Democrat. Retrieved 16 August 2021.
- ^ Robertson, Michelle (20 March 2019). "A poaching conspiracy is playing out on Northern California's coastline". SFGATE. Retrieved 16 August 2021.
- ^ Jensen, Nick; Foy, Patrick (23 July 2021). "Plant poachers threaten California's biodiversity". CalMatters. Retrieved 16 August 2021.
- ^ Alison, Kevin (25 June 2020). "In-vitro cultivation of liveforevers (genus Dudleya) to reduce poaching and extinction". Orange County Chapter of the California Native Plant Society – via Zenodo.
Further reading[]
- Thompson, P. Dudleya and Hassenthaus Handbook. Bonsall Publications. 1993. ISBN 0-9602066-5-5 ISBN 9780960206650
- Treatment from the Jepson Manual
![]() |
Wikimedia Commons has media related to Dudleya. |
- Dudleya
- Crassulaceae genera
- Flora of California
- Crassulaceae stubs