Variegated dudleya | |
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In flower | |
Scientific classification | |
Kingdom: | Plantae |
Clade: | Tracheophytes |
Clade: | Angiosperms |
Clade: | Eudicots |
Order: | Saxifragales |
Family: | Crassulaceae |
Genus: | Dudleya |
Species: | D. variegata |
Binomial name | |
Dudleya variegata | |
Synonyms [1] | |
List
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Dudleya variegata is a deciduous succulent plant in the family Crassulaceae known by the common names variegated liveforever, variegated dudleya or rarely San Diego Hasseanthus. A cryptic plant that survives part of the year dormant underground from starch reserves in a corm, after sufficient rainfall, leaves will emerge, soon giving way to small inflorescences with yellow star-shaped flowers. It is native to Baja California and adjacent San Diego County in California, where it grows in several habitat types, including chaparral and vernal pools.
Although many members of the genus Dudleya are rosette-forming plants with evergreen leaves, this species belongs to the subgenus Hasseanthus, which has diverged into geophytic plants. Species within this subgenus are characterized by small, globose and deciduous leaves similar in appearance and size to the juvenile leaves of plants outside of the subgenus. The stem has evolved into a corm-like unit buried under the surface of the soil, and plants utilize starch reserves within the tuberous root to survive the dry season. The reduced leaves and corm-like caudex are probably paedomorphic adaptations as most Dudleya seedlings have a tuberous caudex and small, drought-deciduous leaves. [2] [3]
This plant has distinctive, often paddle or spoon-shaped leaves with long petioles. The inflorescences contain spreading bright yellow flowers. The stem is an oblong-shaped corm-like structure. Plants can survive the summer without any water, until moisture returns in mid-October, with the leaves finally re-emerging in November. [4]
Plants of this species form 1 to 3 rosettes from the top of the subterranean stem, with each cluster of leaves around 2–6 cm (0.79–2.36 in) wide. The buried stem itself is 1–3 cm (0.39–1.18 in) long, and 3–15 mm (0.12–0.59 in) wide, with a more or less spherical to oblong shape. The leaves are deciduous in summer, and are generally not glaucous, with an oblanceolate or spoon shape. The leaves measure 1–7 cm (0.39–2.76 in) long by 0.5–11 mm (0.020–0.433 in), with the base generally 1–3 mm (0.039–0.118 in) wide, the tip of the leaf shaped acute to obtuse. [5]
The peduncle is 5–20 cm (2.0–7.9 in) tall and 0.5–2 mm (0.020–0.079 in) wide, with 2 to 3 simple, ascending branches. The branches are 2–15 cm (0.79–5.91 in) long, and have 3 to 11 flowers. The flowers are suspended on pedicels 0.5–3 mm (0.020–0.118 in) long. The sepals of the flower are 2–3.5 mm (0.079–0.138 in) long, and shaped deltate-ovate. The petals are 5–8 mm (0.20–0.31 in) long by 2–3.5 mm (0.079–0.138 in) wide, and shaped elliptic. The petals are bright yellow, and have an acute tip. The fruit is spreading, inheriting the characteristic of the flowers. [5]
Plants flower from April to June. Chromosome number is 2n = 34 (n = 17). [5]
This species was first named by botanist Sereno Watson as Sedum variegatum in 1876, based on collections by Daniel Cleveland in San Diego . In 1903, Joseph Nelson Rose and Nathaniel Lord Britton revised the North American Crassulaceae, and placed this taxon as the type species of a new genus, Hasseanthus, and renamed it Hasseanthus variegatus. [6]
In 1945, it was believed that Dudleya multicaulis , at the time called Hasseanthus elongatus, occurred in the Sweetwater River Canyon, at Dehesa, San Diego County. Botanist Reid Moran studied the population and found that, although containing some morphological differences, they were more well-suited to be Hasseanthus variegatus. Plants at this location flower three to four weeks later than typical D. variegata populations elsewhere, and also differ in their greater size and yellower foliage. [7]
In 1953, Reid Moran transferred the genus Hasseanthus as a subgenus of Dudleya on the basis of cytotaxonomic work with Dr. Charles H. Uhl, thus creating the current name. [8]
In the southern part of its range, particularly near Rosarito Beach and Rancho Cuevas in the north of Baja California, plants similar to this species are found that also combine characteristics of Dudleya blochmaniae . They have relatively thick rosette leaves and a habitat closer to D. blochmaniae, but present with yellow odorless flowers. [7]
Dudleya variegata is usually grouped into the subgenus Hasseanthus, a taxonomic rank characterized by diminutive size, deciduous leaves and underground corms. This would have placed it along with 3 other Hasseanthus taxa native to San Diego County, Dudleya blochmaniae , Dudleya brevifolia , and Dudleya multicaulis . [9] [8]
A phylogenetic study from 2013 suggests that the subgenus Hasseanthus is not well-supported by molecular analysis, instead tentatively placing this in a clade which includes the majority of Hasseanthus albeit with the exception of D. multicaulis and the inclusion of D. verityi . [10]
This species is known to hybridize with other members of the genus. These include:
The plant is endemic to an area roughly 80 km long, from San Diego County down into northwestern Baja California, from Tijuana to Ensenada. [5] [11] [13] It occurs in relatively small, disjunct populations from near Black Mountain Ranch in San Diego County to Ensenada. Localities in San Diego County that have or had populations include Black Mountain, Kearney Mesa, Dictionary Hill, San Miguel Mountain, El Cajon, La Mesa, Fletcher Hills, Paradise Hills, Rice Canyon, Dehesa, Otay Mountain, Imperial Beach, and the border near the Otay Crossing. [14] There is also an occurrence at the Silver Strand Training Complex, between Imperial Beach and Silver Strand State Beach. [15]
This species is found typically on dry hillsides and mesas, in foothills and coastal regions usually below 300 m (980 ft). It can be found in the open clearings of chamise, sage scrub or scrub oak brush, on clay lenses and vernal pools. Associates include Ferocactus viridescens , Selaginella cinerascens , and Selaginella bigelovii . [12]
Severe reversals in the population of the variegated dudleya have been the result of continued urban expansion in the United States and Mexico. The rush to develop industrial parks and suburbs along the Mexican-American border near Otay Mesa has led to extensive devastation of major populations and colonies of the plant. Federal tax benefits for these industrial parks encouraged widespread grading on the mesa, eliminating populations of the inconspicuous plant. [12] Recreational activity is also detrimental to the species. [16] [17]
Dudleya virens, the green liveforever or bright green dudleya, is an uncommon species of perennial, succulent plant in the family Crassulaceae, native to several coastal southern California and Baja California locations.
Dudleya, commonly known as liveforevers is a genus of rosette-forming succulent plants in the stonecrop family, Crassulaceae, consisting of about 68 taxa in southwestern North America and Guadalupe Island. The species come in many forms, some large and evergreen, others geophytic and deciduous. Yet, despite their dramatic variations in appearance, most species readily hybridize. The flowers of Dudleya have parts numbered in fives, with the petals arranged in tubular, star-shaped, and bell-shaped forms and, when fruiting, are filled with tiny, ovoid-crescent-shaped seeds.
Dudleya blochmaniae is a summer-deciduous succulent plant known by the common names Blochman's liveforever or Blochman's dudleya. This species of Dudleya survives part of the year with no aboveground presence, surviving as underground corm-like roots in deciduous months. It is characterized by white, star-shaped and spreading flowers that emerge after sufficient rainfall. It is found along the Pacific coast of the California Floristic Province, from the vicinity of San Luis Obispo in California to Punta Colonet in Baja California.
Dudleya caespitosa is a succulent plant known by several common names, including sea lettuce, sand lettuce, and coast dudleya. It is endemic to California, where it grows along the coastline in the southern half of the state. Taxonomically, this species is a highly variable complex of polymorphic and polyploid plants, closely related to numerous neighboring species such as Dudleya farinosa, Dudleya greenei and Dudleya palmeri. It is delimited from neighboring species on an arbitrary basis of distribution and chromosome number, and may not be immediately separable from the other species it approaches.
Dudleya edulis is a species of perennial succulent plant known by the common names fingertips, lady fingers, mission lettuce and the San Diego dudleya. The common name denotes the finger-like shape of the leaves, while the specific epithet edulis refers to the use of the young scapes as food by the Kumeyaay. It is native to Southern California and northern Baja California, and grows on rocky hillsides, cliffs, and bare rock.
Dudleya multicaulis is a succulent plant known by the common name manystem liveforever or many-stemmed dudleya. This Dudleya is endemic to southern California, where it is rare and seriously threatened as its habitat is altered by humans. Many occurrences of this species have been extirpated. This species is characterized by a few short, fingerlike cylindrical leaves with pointed tips, and its erect peduncle, which is topped with a branching inflorescence bearing up to 15 flowers on each long, thin branch. The flowers, which appear in late spring, have pointed yellow petals and long stamens. It is usually found on heavy clay or rocky soils and outcrops.
Dudleya pulverulenta is a species of perennial succulent plant known by the common names chalk lettuce, chalk dudleya, and chalk liveforever. It is one of the largest Dudleya, with a silvery, waxy rosette that may greatly contrast with its habitat. It is also regarded as one of the most distinctive members of the Dudleya, with the most advanced inflorescence in the genus, consisting of pendant, hummingbird pollinated flowers, the longest corolla, and the highest nectar output, along with the largest range of all the Dudleya, over 1,000 kilometres (620 mi), being found from southern Monterey County in California to the Sierra de San Borja in southern Baja California.
Dudleya brevifolia, is a rare succulent plant known by the common name short-leaved liveforever, short-leaved dudleya or rarely the Del Mar Hasseanthus. It is an edaphic endemic that only grows on Lindavista formation marine terraces, on surfaces with ironstone nodules. The leaves are deciduous, and disappear after the inflorescence develops. The small white flowers are star-shaped with a yellow center. After flowering, any above ground trace of the plant will disappear, and it survives under the earth with a starch-rich subterranean caudex. Dudleya brevifolia is only found on coastal mesas along a small strip of coast in San Diego County, California.
Dudleya greenei is a perennial species of succulent plant known by the common names Greene's liveforever, or Greene's dudleya. It is endemic to the Channel Islands of California, where it grows along the cliffs of four of the eight islands. It is a highly variable plant, presenting with multiple forms and varying levels of ploidy. Taxonomically, this species is an insular segregate of Dudleya caespitosa, and was placed as a stopgap taxon by Reid Moran in his 1951 thesis on the genus. It is characterized by white or green leaf rosettes, loomed over by inflorescences bearing pale yellow to white flowers. It is a member of the subgenus Dudleya, as it cannot be propagated from leaf cuttings, does not grow from a corm, and has tight petals.
Dudleya gnoma is a rare species of succulent plant in the stonecrop family known by the common names munchkin liveforever and munchkin dudleya. It is characterized by its diminutive stature, small yellow flowers, and distinctive white rosettes. It is endemic to the eastern portion of Santa Rosa Island, one of the Channel Islands of California, where it is known from one population at the type locality, containing three colonies of plants.
Dudleya attenuata is a species of perennial succulent plant known by the common name taper-tip liveforever, native to Baja California and a small portion of California. A rosette-forming leaf succulent, it has narrow pencil shaped leaves that can often be found covered in a white epicuticular wax. The thin, sprawling stems branch to form the clusters of rosettes, with plants creating a "clump" up to 40 cm wide. The small flowers are white or yellow, with 5 spreading petals. It is a diverse, variable species that extends from the southernmost coast of San Diego County to an area slightly north of the Vizcaino Desert, hybridizing with many other species of Dudleya in its range. Some plants with white or pinkish flowers were referred to as Orcutt's liveforever, referring to a former subspecies split on the basis of the flower color.
Dudleya ingens is a species of perennial succulent plant in the family Crassulaceae commonly known as the rock liveforever or Baja liveforever. A relatively large member of the genus Dudleya, this species has long green succulent leaves, and in April to June is characterized by pale yellow to white pink-tinged flowers topping tall, reddish inflorescences. It has a stem clothed densely with old, leathery leaves, and the inflorescence may be nodding, with the floral branches bearing the flowers tending to unfurl like the fronds of a fern. It is similar in appearance to Dudleya brittonii, but differs in range and chromosome number. This species is endemic to the state of Baja California in Mexico, being found from Santo Tomás to the southern coast of the state.
Dudleya hendrixii is a species of succulent plant known by the common name Hendrix's liveforever. It is a rare endemic restricted to undisturbed habitat near in the vicinity of Punta Colonet, Baja California, Mexico. The species is a small succulent that grows from an underground stem, producing small flowers in late spring to early summer before becoming summer deciduous and dormant. It was discovered in late 2016 by researchers from San Diego State University and the University of California, Santa Cruz, and is named in honor of the late musician Jimi Hendrix.
Dudleya guadalupensis is a very rare species of succulent perennial plant in the family Crassulaceae commonly known as the Guadalupe liveforever. It is a rosette-forming leaf succulent, with foliage that is variously colored light green, green, and a waxy white. It is characterized by dense leaves that fold over the center in dormancy, a curving, sinuous flower stalk, and white, cup-shaped flowers. It is endemic to the rocks and islets off of Guadalupe Island, an isolated volcanic island in the Pacific Ocean located 241 kilometers off of the coast of Baja California.
Dudleya anomala is a rare species of succulent plant in the family Crassulaceae commonly known as the Todos Santos liveforever. With a dense, cushion-forming habit, this leaf succulent is characterized by elongated stems, slightly sticky leaves, and bell-shaped flowers with white, spreading petals. This species is native to Baja California, Mexico, and is found primarily on islands and one coastal locality.
Dudleya cultrata is a species of perennial succulent in the family Crassulaceae commonly known as the knife-leaved liveforever or the maritime succulent liveforever. This species is characterized by oblong, narrow green leaves and flowers with pale yellow petals that bloom from April to June. Although similar to Dudleya ingens, this species is most often seen growing sympatric with the larger, wax-covered Dudleya anthonyi. It is native to Baja California, occurring on the coast from Punta Colonet and San Quintin to El Rosario.
Dudleya nubigena is a species of succulent plants in the family Crassulaceae. It is a rosette forming perennial with flattish leaves. Endemic to southern Baja California Sur, the species is found in the Sierra de la Laguna and the surrounding lowlands, a small southern portion of the Sierra de la Giganta, and on Isla Espíritu Santo, with a subspecies endemic to Cerralvo Island.
Dudleya cymosasubsp. pumila, most commonly known as the low canyon dudleya, chalky canyon dudleya or California live-forever, is a species of perennial succulent plant. It has diamond to spoon shaped leaves, sometimes coated with a fine white powder, and in May through July, bright red, orange or yellow flowers adorn the short inflorescence. A leaf succulent primarily found growing in rocky cliffs and slopes, it is endemic to California, and grows in the Transverse Ranges and South Coast Ranges, with some outlying populations. A variable plant, in some localities it is difficult to distinguish from other plants in the genus.
Dudleya crassifolia is a species of drought deciduous, corm-forming succulent plant known by common name as the thick-leaf dudleya. It is an incredibly rare and cryptic plant native to one small locale less than a hectare in area on the Colonet peninsula in Baja California. It is threatened by urban development, including a proposed seaport. It is characterized by white, spreading flowers with leaf bases that are persistent on the stem. Although it did not receive as much media attention as the neighboring Dudleya hendrixii, it has been noted that the plant has several similarities to cryptic succulents like Anacampseros.
Dudleya saxosasubsp. aloides is a species of perennial succulent plant in the family Crassulaceae known by the common names desert dudleya or desert savior. It is a rosette-forming species widely distributed throughout the Peninsular Ranges and desert mountains of California in the United States. It is characterized by bright-yellow or greenish-yellow flowers, and can be found in shaded crevices and slopes. Plants in western half of the range may grade into Dudleya lanceolata.