Dudleya cymosa subsp. agourensis

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Dudleya cymosa subsp. agourensis
Dudleya cymosa agourensis 27308321647.jpg
Status TNC T1.svg
Critically Imperiled  (NatureServe) [1]
Scientific classification Red Pencil Icon.png
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Eudicots
Order: Saxifragales
Family: Crassulaceae
Genus: Dudleya
Species:
Subspecies:
D. c. subsp. agourensis
Trinomial name
Dudleya cymosa subsp. agourensis
K.M.Nakai
Synonyms [2]
  • Dudleya agourensis(K.M.Nakai) P.H.Thomson

Dudleya cymosasubsp. agourensis, commonly known as the Agoura Hills dudleya or Agoura Hills liveforever, is a species of perennial succulent plant. A rare and critically imperiled species from the Santa Monica Mountains in California, it is characterized by glaucous, gray-purple leaves, bright yellow flowers, and ascending bracts. A leaf succulent, it is found growing on west to northwest-facing open, rocky volcanic slopes. [3]

Contents

It was formerly considered to be a distinct race within Dudleya cymosa subsp. ovatifolia, until it was described in 1987 on the basis of numerous differences that distinguished it from that subspecies, namely the leaf morphology, the branching caudex, and the morphology of the flowers and inflorescences. [4] Although subsp. ovatifolia was split, this species has inherited its listed status as threatened under the Endangered Species Act. [5] It is primarily threatened by development, but also trampling, trails, invasive plants, and illegal dumping. [1]

Description

This species grows in a caespitose habit, with 1 to 6 or more rosettes on a branching stem. The rosettes are 5–10 cm (2.0–3.9 in) wide. The stems are 1–2 cm (0.39–0.79 in) wide. The 6 to 10 leaves on the rosette are oblong to lanceolate-shaped. The leaf surfaces are often glaucous but not farinose, and are colored a purple-gray to blue-gray. The leaves measure 3–10 cm (1.2–3.9 in) long by 1–1.5 cm (0.39–0.59 in) wide, and have an acute to acuminate tip. When dry, the leaves may become twisted. [3] [4] [6]

The inflorescence is more or less asymmetric radially when it branches. The erect peduncle is 6–17 cm (2.4–6.7 in) tall by 2–3 mm (0.079–0.118 in) wide, and tinged with red. Lining the peduncle are lanceolate bracts, which are 1–2.5 cm (0.39–0.98 in) long by 7–10 mm (0.28–0.39 in) and with acute to acuminate tips. The lower bracts are ascending. The inflorescence is composed of 2 to 3 simple to bifurcate branches, with their terminal branches ascending. The terminal branches are 1–3 cm (0.39–1.18 in) long with 3 to 8 flowers. The lowermost pedicels suspending the flowers are 6–12 mm (0.24–0.47 in) long. [3] [4]

The tips of the flower buds are angled greater than 50°. The flower petals are a bright yellow, and occasionally glaucous along their midrib. The apices of the petals are spreading 45° to 90°. The petals measure 10–12 mm (0.39–0.47 in) long by 3–4.5 mm (0.12–0.18 in) wide. [3] [4] [6]

Flowering is from May to June. Chromosome count is n = 17 ( 2n = 34). [3] [4] [6]

Distribution and habitat

Dudleya cymosa subsp. agourensis is endemic to California in the United States, occurring in the Santa Monica Mountains of the Transverse Ranges. It is found in Ventura County and Los Angeles County. All occurrences of this species are found in a 2 mi (3.2 km) by 6 mi (9.7 km) band along the north-facing side of the western Santa Monica Mountains, between Thousand Oaks and Agoura Hills. [5]

This species is primarily found on open, rocky volcanic slopes, typically facing west to northwest. It is also found along road embankments. Although rare, it can be locally abundant where found. It occurs in a drier, more exposed habitat than Dudleya cymosa subsp. ovatifolia . [3] [4]

Related Research Articles

<i>Dudleya abramsii <span style="font-style:normal;">subsp.</span> setchellii</i> Species of succulent

Dudleya abramsiisubsp. setchellii, known by the common name Dudleya setchellii, the Santa Clara Valley dudleya, or Santa Clara Valley liveforever, is a member of the Dudleya genus of succulent perennials, members of the family Crassulaceae. The Santa Clara Valley dudleya, endemic to the Santa Clara Valley region in the southern San Francisco Bay Area, was listed on 3 February 1995, as an endangered species. It is considered to be a subspecies of Dudleya abramsii, but its taxonomic status is still unclear. Its closest relative is Dudleya cymosa subsp. paniculata, which is a morphologically similar sister taxon.

<i>Dudleya cymosa</i> Species of succulent

Dudleya cymosa is a species complex of evergreen and deciduous succulent plants in the family Crassulaceae known by the common name: canyon liveforever. It is a loosely defined polyphyletic species with a diverse number of subspecies, varying highly in morphology, distribution, and habitat.

<i>Dudleya candelabrum</i> Species of succulent

Dudleya candelabrum is a species of succulent plant known by the common names candleholder liveforever or candleholder dudleya. 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.

<i>Dudleya densiflora</i> Species of succulent

Dudleya densiflora is a species of succulent plant in the family Crassulaceae known commonly as the San Gabriel Mountains liveforever or San Gabriel Mountains dudleya. A very rare plant confined to the San Gabriel Mountains of Los Angeles County, California, it is known only from three to five spots in the mountain range, with an estimated 1,700 individual plants remaining. Growing in the cracks of the granite slopes of three canyons in this single mountain range, it is threatened by human activity such as rock quarrying and off-trail recreation.

<i>Dudleya lanceolata</i> Species of succulent

Dudleya lanceolata is a succulent plant known by the common name lanceleaf liveforever or lance-leaved dudleya. It is an extremely variable and widely ranging species that occurs from Monterey County and Kern County in California south through Ensenada in Baja California. It is characterized by green to purple lanceolate leaves, red, orange, or less commonly yellow petals, and is typically tetraploid. Despite its diversity, it is quite stable as a species, but hybrids may be discovered with other species of Dudleya, which can make it difficult to discern in areas where numerous species converge.

<i>Dudleya multicaulis</i> Species of succulent

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 becoming increasingly uncommon as its habitat is altered. This plant grows few short, fingerlike cylindrical leaves with pointed tips. It is dominated by its erect peduncle, which is topped with a branching inflorescence bearing up to 15 flowers on each long, thin branch. The flowers have pointed yellow petals and long stamens.

<i>Dudleya abramsii</i> Species of succulent

Dudleya abramsii is a species complex of succulent plants native to California and parts of Baja California. There are numerous subspecies, some critically endangered, with varying habits and lifestyles, but most often characterized by a smaller size, yellow flowers, and an affinity for rocky habitats. The subspecies may be polyphyletic.

<i>Dudleya verityi</i> Species of succulent

Dudleya verityi is a rare species of succulent plant known by the common name Verity's liveforever. It is endemic to Ventura County, California, where it is known from only three occurrences in the vicinity of Conejo Mountain between Camarillo and Thousand Oaks. It probably occurs in a few additional locations nearby which have not yet been officially vouchered.

<i>Dudleya gnoma</i> Species of succulent plant

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.

<i>Dudleya attenuata</i> Species of succulent

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.

<i>Dudleya ingens</i> Species of succulent

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 appear 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.

<i>Dudleya guadalupensis</i>

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.

<i>Dudleya campanulata</i> Succulent plant native to Baja California, Mexico

Dudleya campanulata is a species of perennial succulent plant known by the common name as the Punta Banda liveforever, native to Baja California and endemic to the Punta Banda peninsula, a promontory south of Ensenada that encloses the southern limit of the Bahía de Todos Santos, a deepwater bay. One of many species of Dudleya native to the peninsula and surrounding islands, it is distinguished by its campanulate flowers and its occupation of a narrow habitat that consists of ocean bluffs on the southern end of the Punta Banda, near the well-known blowhole La Bufadora.

<i>Dudleya saxosa <span style="font-style:normal;">subsp.</span> collomiae</i>

Dudleya saxosa subsp. collomiae, known by the common name Gila County liveforever, is a subspecies of perennial succulent plant within the genus Dudleya native to central Arizona. It is characterized by showy bright-yellow flowers on an upright inflorescence colored pink, red or orange. The leaves are green or covered in a white, powdery wax. This species is found growing in rocky slopes, canyons, and crevices, and often on Sonoran Desert sky islands.

<i>Dudleya abramsii <span style="font-style:normal;">subsp.</span> affinis</i> Subspecies of plant

Dudleya abramsii subsp. affinis, commonly known as the San Bernardino Mountains Dudleya, is a subspecies of succulent plant endemic to a portion of the San Bernardino Mountains in California. It is a plant with an unbranching stem and elliptical leaves occurring in Green Canyon and the nearby plateaus.

<i>Dudleya cymosa <span style="font-style:normal;">subsp.</span> paniculata</i> Species of succulent plant

Dudleya cymosa subsp. paniculata, known by the common name Diablo Range dudleya, is a species of perennial succulent plant in the family Crassulaceae native to the Inner South Coast Range of California. It is characterized by pale yellowish flowers, oblong to oblanceolate leaves and a growth habit not limited to a single substrate. It is closely related to Dudleya abramsii subsp. setchellii.

Dudleya cymosasubsp. costatifolia, known commonly as the Pierpoint Springs dudleya or the Pierpoint Springs liveforever, is a species of succulent plant in the family Crassulaceae, narrowly endemic to a locality in Tulare County, California, United States. It is a clumping plant with small rosettes and bright yellow flowers, resembling alpine "cushion plants."

<i>Dudleya cymosa <span style="font-style:normal;">subsp.</span> pumila</i> Subspecies of plant

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.

<i>Dudleya cymosa <span style="font-style:normal;">subsp.</span> cymosa</i> Subspecies of succulent perennial plant

Dudleya cymosasubsp. cymosa is a species of succulent perennial plant in the family Crassulaceae native to California. It is the autonymous subspecies for Dudleya cymosa, and is known by the common name canyon liveforever. It is native to the California Coast Ranges, the Sierra Nevada and the Santa Monica Mountains. It is characterized by bright-yellow, orange or red flowers and broad, wide leaves. This plant is commonly found growing on rocky outcrops, talus slopes, and in shaded canyons.

<i>Dudleya cymosa <span style="font-style:normal;">subsp.</span> marcescens</i> Subspecies of deciduous succulent plant

Dudleya cymosa subsp. marcescens is a species of summer-deciduous succulent plant known commonly as the marcescent dudleya or marcescent liveforever. Throughout the months of spring, it is characterized by a bloom of small, bright-yellow flowers with 5 petals, tinged with orange or red. It is a leaf succulent with a basal rosette, with the foliage withering in summer, going completely leafless, a neotenous trait in the genus. This species is endemic to the exposed volcanic rock of the Santa Monica Mountains in California, being found on shady slopes and outcroppings. It differs from its local congeners with its deciduous habit, slender caudex, and narrower leaf shape, although it is superseded in some of these characteristics by Dudleya parva, growing 13 km to the north, which has even narrower leaves and is quicker to lose them. Because of its restricted distribution and small size, it is vulnerable to habitat degradation and disturbance from acts of graffiti and rock climbers. It is listed as threatened by the United States Fish and Wildlife Service.

References

  1. 1 2 "Dudleya cymosa ssp. agourensis". NatureServe Explorer. Arlington, Virginia: NatureServe. 2022. Retrieved 22 April 2022.
  2. "Dudleya cymosa subsp. agourensis". Plants of the World Online . Royal Botanic Gardens, Kew . Retrieved 22 April 2022.
  3. 1 2 3 4 5 6 McCabe, Stephen W. (2012). "Dudleya cymosa subsp. agourensis". Jepson eFlora. Jepson Flora Project. Retrieved 22 April 2022.
  4. 1 2 3 4 5 6 Nakai, Kei M. (1987). "Some New and Reconsidered California Dudleya (Crassulaceae)". Madroño. 34 (4): 339–344.
  5. 1 2 "Santa Monica Mountains Dudleya (Dudleya cymosa subsp. ovatifolia and Dudleya cymosa subsp. agourensis) 5-Year Review: Evaluation and Summary" (PDF). ECOS Environmental Conservation Online System. U.S. Fish and Wildlife Service, Ventura Fish and Wildlife Office, Ventura, California: U.S. Fish & Wildlife Service. Retrieved 22 April 2022.
  6. 1 2 3 Moran, Reid. "Dudleya cymosa subsp. agourensis". In Flora of North America Editorial Committee (ed.). Flora of North America North of Mexico (FNA). New York and Oxford. Retrieved 22 April 2022 via eFloras.org, Missouri Botanical Garden, St. Louis, MO & Harvard University Herbaria, Cambridge, MA.