Dudleya candelabrum

Dudleya candelabrum is a species of succulent plant known by the common names candleholder liveforever[1] or candleholder dudleya.[2] Endemic to California, this species grows wild only on the northern Channel Islands, where it is found in open rocky places and north-facing slopes. It is characterized by thin, spade-shaped green leaves and an inflorescence covered in long, reflexed bracts, with pale yellow flowers. It has been threatened by poachers shipping plants to South Korea.[3]

Dudleya candelabrum
Scientific classification Edit this classification
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Eudicots
Order: Saxifragales
Family: Crassulaceae
Genus: Dudleya
Species:
D. candelabrum
Binomial name
Dudleya candelabrum
Synonyms
  • Cotyledon candelabrum Fedde
  • Echeveria candelabrum Berger

Description
At the Regional Parks Botanic Garden.

This species typically grows from an often solitary basal rosette up to half a meter wide atop a thick, hardy caudex that is swollen at the base. There are 20 to 45 evergreen leaves on the rosette. The leaves are a pale green to pinkish-green, shaped obovate to oblong-oblanceolate, and more or less thin. The leaves may be glaucous, and when torn from the rosette, leave a purple-red wound. Each leaf measures anywhere from 6–22 cm (2.4–8.7 in) long by 3–7 cm (1.2–2.8 in) wide, with an acuminate tip.[2]

The unbranched peduncle is generally erect but often bending under the weight of the inflorescence it holds. The peduncle is usually 15–54 cm (5.9–21.3 in) tall while only 6–11 mm (0.24–0.43 in) wide. The bracts are long and reflexed, bending backwards. The lowermost bracts are 1–4 cm (0.39–1.57 in) long. The inflorescence first branches 3 to 7 times, and then those branch another 1 to 2 times. The terminal branches are 2.5–13 cm (0.98–5.12 in) and hold up to 25 flowers. The flower has pale-yellow petals 8–12 mm (0.31–0.47 in) long within its pink-tinged green sepals.[4][5]

Flowering is from May to July. Chromosome number is 17.[5]

Taxonomy

Taxonomic history

The type specimen was collected by Professor E. L. Greene on Santa Cruz Island, in July and August 1886. The species was described in 1903 with Nathaniel Lord Britton and Joseph Nelson Rose's taxonomic revision of North American Crassulaceae, as part of the creation of the genus Dudleya.[6] Later, German botanists such as Fedde in 1904 and Berger in 1930 would classify it as Cotyledon candelabrum and Echeveria candelabrum respectively, but these redefinitions were outdated after Reid Moran's revision of the genus, along with later phylogenetic work that showed Dudleya as being more closely related to Sedum than to Echeveria.[7]

Characteristics

Reid Moran noted the resemblance of the plant to the green form of Dudleya brittonii.[4] Phylogenetic analysis has shown that it is instead related to Dudleya acuminata, a geographically distant plant that shares the trait of shiny green leaves.[7]

Despite the characteristic green leaves, however, some individuals may instead have white, glaucous leaves, which makes them difficult to distinguish from the polymorphic Dudleya greenei. The two may be keyed by the fact that D. candelabrum is found in steep, inland to coastal canyons, on often north-facing or shaded cliffs, or on deeper soils than D. greenei, and the fact that D. candelabrum has long, reflexed bracts.[8]

Distribution and habitat

Dudleya candelabrum is endemic to the Santa Cruz and Santa Rosa Islands. It occurs on rocky, north-facing slopes below 1,200 ft.[9]

Conservation

In 2020, social media posts indicated that numerous plants were poached from California and destined for South Korea.[3][10]

References
  1. "Dudleya candelabrum". Calflora. Archived from the original on 2021-04-15. Retrieved 15 August 2021.
  2. McCabe, Stephen W. (2012). "Dudleya candelabrum". Jepson eFlora. Jepson Flora Project. Retrieved 2 April 2022.
  3. Bradford, Steven (2021). "AB 223 Bill Analysis" (PDF). California State Senate Public Safety Committee – via California Senate.
  4. Moran, Reid. "Dudleya candelabrum Rose [family CRASSULACEAE]". Flora of North America. 8 – via JSTOR.
  5. Thomson, Paul H. (1993). Dudleya and Hasseanthus Handbook. Bonsall, California: Bonsall Publications. p. 61. ISBN 9780960206650.
  6. Rose, Joseph Nelson (1904). "Dudleya Candelabrum Rose, sp. nov". Bulletin of the New York Botanical Garden. 3 (9): 17.
  7. 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. doi:10.1600/036364413X674760. S2CID 15715233.
  8. Stephen Ward, McCabe (1997). "Dudleya gnoma (Crassulaceae): A new species from Santa Rosa Island". Madroño. 44: 48–58 – via JSTOR.
  9. "Dudleya candelabrum". Native Plant Database. Theodore Payne Foundation. Archived from the original on 2021-05-15.
  10. Jensen, Nick (Spring 2021). "New Protections for Dudleya?" (PDF). Flora. 4: 30 – via California Native Plant Society.
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