Dudleya attenuata
| Dudleya attenuata | |
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Scientific classification 
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| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Angiosperms |
| Clade: | Eudicots |
| Order: | Saxifragales |
| Family: | Crassulaceae |
| Genus: | Dudleya |
| Species: | D. attenuata
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| Binomial name | |
| Dudleya attenuata (S. Watson) Moran
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| Distribution of Dudleya attenuata subsp. attenuata (red) and Dudleya attenuata subsp. australis (green) | |
| Synonyms[1][2] | |
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Dudleya attenuata, known by the common names including Orcutt's live-forever and taper-tip liveforever, is a species of perennial succulent plants native to California and to Baja California.[3]
Description[]
A plant may have anywhere from 3 to 50 rosettes emerging from the caudex. Caudex is 3 to 15 mm wide. Leaves of this species are evergreen and farinose. The base of the foliage is flushed with a purple to red hue. Flowers are open rather than tubular, borne in cymes with only 1-3 simple branches, hence with fewer flowers than most related species. Flowering occurs from May through June.[3][4]
Taxonomy[]
Subdivisons[]
| Name | Authority | Common name | Distribution |
|---|---|---|---|
| Species Dudleya attenuata (S. Watson) Moran | |||
| D. a. subsp. attenuata[4][5] | |||
| subsp. attenuata
syn. subsp. orcuttii syn. D. orcuttii syn. Stylophyllum orcuttii |
(S. Watson) Moran
(Rose) Moran (Rose) P.H. Thomson Rose |
Taper-tip liveforever
Orcutt's liveforever |
Occurs in northern Baja California, with a small population in San Diego County in the Border Field State Park. The southern range of the diploid subspecies ends near El Rosario. |
| The caudex is erect to sprawling, 3 to 15 mm thick. growing up to 30 cm or more long, branching to form clumps 10 to 40 cm wide, often covered in dried leaves. Rosettes are 2 to 5 cm wide, of 5 to 20 erect leaves. Leaves are farinose, linear to linear-oblanceolate, acute, terete, 2 to 10 cm long, 2 to 5 mm wide, with the base lenticular to suborbicular or oval 5 to 15 mm wide, 2 to 4 mm high, but sometimes higher than wide.[4][6]
Peduncles are 5 to 30 cm tall, 1 to 3 mm thick, leafy to within 1 to 4 cm of the base. The 5 to 15 bracts on the stem are ascending, linear-lanceolate to deltate-ovate, acute, with the lowermost 0.5 to 8 cm long and 2 to 5 mm wide. Higher on the inflorescence, it is composed of 1 to 3 simple branches 2 to 15 cm long, with 3 to 15 erect flowers mounted on pedicels 0.5 to 3 mm long.[4][6] On the flower, the calyx is 3 to 6 mm wide, 2 to 5 mm high, segmented into deltate-ovate sepals with an acute tip, 1.5 to 4 mm long, 1 to 2 mm wide. The corolla is cream, white or pinkish, with the keel finely marked in red. Petals are 5 to 11 mm long, 1.5 to 4 mm wide. Concerning the stamens, filaments are 3.5 to 11 mm long, and the anthers are red to yellow, 1 to 2 mm long. Seeds are reddish brown, 0.7 to 1 mm long. Plants are diploid, typically with n = 17 chromosomes.[4][6] | |||
| D. a. subsp. attenuata (syn. D. a. ssp. orcutti) Punta Banda specimens | |||
| A form occurs on the Punta Banda in Ensenada that is identical to a typical ssp. attenuata, but phylogenetic analysis has revealed that it is not sister to D. attenuata, instead being basal to Dudleya formosa and Dudleya edulis. The plant is diploid or tetraploid, with 17 or 34 chromosomes.[7] | |||
| D. a. subsp. attenuata (syn. D. a. ssp. orcutti) El Rosario form | |||
| A second cytological form occurs near and around the coast of El Rosario, almost identical in appearance with a typical ssp. attenuata plant. The petals tends to be slightly longer than in diploids and floral parts slightly larger. This form is a tetraploid with 34 chromosomes, as opposed to 17.[6][8] | |||
| Hybrids of subsp. attenuata[5][6] | |||
| × D. candida | Moran & SDNHM | Coronados hybrid liveforever | Occurs on the Coronado Islands. |
| × D. edulis | '' | La Mision hybrid liveforever | Occurs in the vicinity of La Misión, Baja California. |
| × D. formosa | '' | Guadalupe Valley hybrid liveforever | Occurs in the Guadalupe Valley northeast of Ensenada. |
| × D. ingens | '' | Colonet hybrid liveforever | Occurs near Colonet and San Quintín, Baja California. |
| × semiteres†
syn. Dudleya × semiteres syn. Cotyledon semiteres syn. Echeveria semiteres syn. Stylophyllum semiteres |
(Rose) Moran
(Rose) Moran (Rose) Fedde (Rose) Berger Rose |
Baja California hybrid liveforever | Occurs along the Pacific coast just north of Ensenada and on South Coronado & South Todos Santos islands. |
| Caudex 1 to 3 cm thick, up to 15 cm high, branching to form clumps of 10 to 15 rosettes. Rosettes are 3 to 10 cm wide, of 15 to 30 ascending leaves. Leaves are green or glaucous, tapering uniformly with the sides roughly parallel in the bottom half. The leaves have a flattish or slightly convex ventral surface, and a convex dorsal surface, with the margins acute in the lower quarter of the plant but rounded towards the tip. Leaves are 3 to 10 cm long, 6 to 15 mm wide, and 3 to 6 mm thick.[9]
Peduncle is 10 to 30 cm tall, 3 to 8 mm thick. Bracts are deltate-lanceolate, acute, with the lowermost 1 to 3 cm long, 3 to 7 mm wide. The inflorescence is composed of typically 2 to 4 ascending branches, with each branch typically 3 to 10 cm long. 3 to 12 flowers are mounted on the pedicels, of which, the lowermost pedicels are 3 to 8 mm long.[9] On the flower, the calyx is 4 to 5 mm wide, 4 to 6 mm high, segmenting into deltate-ovate to lanceolate sepals that are 3 to 5 mm long and 1.5 to 2 mm wide. Petals are white or cream, often with the keels lined in red, similar to D. a. subsp. attenuata. Petal shape is elliptic-oblong, acute, 8 to 10 mm long, 2 to 3.5 mm wide. The stamens are composed of filaments 5 to 6.5 mms long, with red or yellow anthers 1 to 1.5 mm long. × semiteres shares the chromosome count with its parents, having a chromosome number of n = 17.[9] | |||
| × D. variegata | Moran & SDNHM | Tijuana hybrid liveforever | Occurs near Tijuana and the Mexico–United States border. |
| D. a. subsp. australis[5] [6] | |||
| subsp. australis | Moran | Southern taper-tip liveforever | Occurs along the coast of Baja California, from 50 miles south of El Rosario to near the village of . |
| Caudex 4 to 8 mm thick. On the inflorescence, the pedicels are 2 to 12 mm long. On the flower, the corolla is white, but with some markings of red on the keel. Petals are 7 to 11 mm long, 3 to 4 mm wide. Subspecies australis is distinguished by its octoploid chromosome count. Chromosomes n = 68.[6] | |||
| Hybrids of subsp. australis[5][6] | |||
| × | Moran | Hybrid white-flower liveforever | Occurs near Puerto Faro San José, Baja California. |
| Chromosomes n = 34 and n = 51.[6] | |||
| † Likely a hybrid between D. a. subsp. attenuata and either D. brittonii or D. candida[5] | |||
Phylogeny[]
The taxonomic status of D. attenuata's subspecies is still under debate. Phylogenetic analysis reveals that although some specimens of D. attenuata from Punta Banda are sister to D. a. subsp. attenuata, other specimens collected are instead basal to D. edulis and D. formosa, illustrating the gene flow where the species overlap.[7]
Distribution and habitat[]
D. attenuata is nearly endemic to Baja California with the exception of a population north of the border in San Diego County, California, at the Border Field State Park. It is also occurrent offshore on the Coronado Islands and the Isla Todos Santos. It can be found on coastal bluffs, typically below 165 ft.
Conservation[]
The D. attenuata population in the United States is threatened by Border Patrol activity and trampling.[10]
References[]
- ^ Tropicos Dudleya attenuata
- ^ The Plant List, Dudleya attenuata
- ^ Jump up to: a b Flora of North America, v 8 p 176.
- ^ Jump up to: a b c d e Ward McCabe, Stephen (2012). "Dudleya attenuata subsp. attenuata". Jepson eFlora. Jepson Flora Project.
- ^ Jump up to: a b c d e Rebman, J. P.; Gibson, J.; Rich, K. (2016). "Annotated checklist of the vascular plants of Baja California, Mexico" (PDF). San Diego Society of Natural History. 45: 133.
- ^ Jump up to: a b c d e f g h i Moran, Reid (2001). "Dudleya attenuata, with the new subspecies australis". Haseltonia. Etter, Julia & Kristen, Martin – via https://www.crassulaceae.com/crassulaceae/crashome_en.asp.
- ^ Jump up to: a b 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). Systematic Botany, 38(4), 1096-1104.
- ^ Thomson, Paul H. (1993). Dudleya and Hasseanthus Handbook. Bonsall Publications.
- ^ Jump up to: a b c Moran, Reid (1952). "Dudleya X semiteres (Rose) Moran, status novus". Desert Plant Life – via Crassulaceae.com.
- ^ "Dudleya attenuata orcutti". Native Plant Database. Theodore Payne Foundation. Retrieved 15 August 2021.
- Dudleya
- Flora of California
- Flora of Baja California
- Natural history of San Diego County, California
- Natural history of the California chaparral and woodlands
- Taxa named by Reid Venable Moran