Dudleya brevifolia

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Dudleya brevifolia
Dudleya Brevifolia flowering at Crest.png
Short-Leaved Dudleya.JPG
Flowering (top) and developing inflorescence (bottom)
Status TNC G1.svg
Critically Imperiled  (NatureServe)
Scientific classification OOjs UI icon edit-ltr.svg
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Eudicots
Order: Saxifragales
Family: Crassulaceae
Genus: Dudleya
Species:
D. brevifolia
Binomial name
Dudleya brevifolia
(Moran) Moran
Dudleya brevifolia distribution map Ver. 2.jpg
Natural range of Dudleya brevifolia
green - D. brevifolia
† red - D. brevifolia × D. variegata
† blue - Introgressive populations with D. blochmaniae ssp. blochmaniae
† purple - D. blochmaniae ssp. blochmaniae

Daggers (†) represent extirpated populations. Populations on the map are given a name based on locality or collector.

Contents

Synonyms

Dudleya blochmaniae subsp. brevifolia Moran [1] [2]

Dudleya brevifolia, [1] [2] is a rare succulent plant known by the common name short-leaved liveforever, short-leaved dudleya or rarely the Del Mar Hasseanthus. [3] 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.

It was formerly a subspecies of the similar Dudleya blochmaniae , and was not recognized as a distinct species because both plants grew and hybridized together. [4] However, the habitats with the intermediate populations were razed for residential development, and with these populations destroyed, Dudleya blochmaniae subsp. brevifolia was elevated to species status as Dudleya brevifolia. [5] Populations continued to be extirpated until the plant was protected. Currently, Dudleya brevifolia is only found in 5 locations in the world, in an area roughly 8 square miles (21 square kilometres) centered around Torrey Pines State Natural Reserve. It is of conservation concern, as the remaining populations have become fragmented and are threatened by continued disturbance and declining populations at some sites. [6]

Description

In comparison with a ruler, demonstrating the minuscule size of this succulent. Short-leaved liveforever 5.jpg
In comparison with a ruler, demonstrating the minuscule size of this succulent.

This species is unique as the smallest member of the Dudleya . It is characterized by the ultimate leaf reduction in the genus, having the smallest and most divergent leaf type, which are often almost buried in the soil, and connected to the stem by long petioles. This species is neotenous, with the adult leaves essentially remaining unchanged from the juvenile leaves. [7]

A plant with a sole flower compared to a dime. DUDBRE3.jpg
A plant with a sole flower compared to a dime.

The leaves are deciduous, and expire towards the summer months. The flowering period usually begins as early as April, and continues through June, with seeds being set in June and July. The populations at Carmel Mountain Preserve tend to flower earlier than those near the coast. [8] [2]

Morphology

While the majority of species of Dudleya tend to have woody, above-ground stems, in this species the stem has been reduced to a subterranean, corm-like structure. This corm is elongate, and measures 1.5–3.5 cm (0.59–1.38 in) long by 1–6 mm (0.039–0.236 in). Emerging from the corm are the rosettes of basal leaves, with usually one rosette of leaves per plant, but sometimes increasing to up to 3. The rosettes measure 0.5–4 cm (0.20–1.57 in) wide. There are 5 to 15 basal leaves, more or less spheric to spoon-shaped distally, which are usually buried in the soil except for the top surface of each leaf blade. The leaves measure 0.7–1.5 cm (0.28–0.59 in) long by 2–7 mm (0.079–0.276 in) wide and 2–4 mm (0.079–0.157 in) thick. The leaves have a long, narrow petiole connecting them to the stem. [1] [7]

The peduncle is 2–11 cm (0.79–4.33 in) tall by 0.5–1 mm (0.020–0.039 in). The peduncle is covered in 10 to 20 bracts. The bracts are shaped triangular-ovate to sub-orbiculate (nearly circular) or reniform (kidney-shaped). The bracts measure 0.2–1 cm (0.079–0.394 in) long by 2.5–8 mm (0.098–0.315 in) wide and 2–6 mm (0.079–0.236 in) thick, with the tip of bracts obtuse. The lower bracts are less than 1.5 × longer than they are wide. The terminal branches (cincinni) on the inflorescence, of which there are typically very few, measure 1–4 cm (0.39–1.57 in) long and have 3 to 10 flowers. [1] [7]

The flowers are white and star-shaped, with a yellow center. The petals are connate 0.7 mm (0.028 in), and spread from near the middle. They are white, colored pinkish on the keel, turning yellow towards the center, and are also often lined with red. The shape of the petals is elliptic, and they measure 5–8.5 mm (0.20–0.33 in) long by 2–3.5 mm (0.079–0.138 in) wide, with the apex subobtuse. The entire corolla measures 8–15 mm (0.31–0.59 in) in diameter. The flowers tend to have a musky-sweet odor. [7]

Taxonomy

Taxonomic history

The plant was first collected by F. W. Peirson at Torrey Pines in 1922. Willis L. Jepson, in line with the common scientific view at the time, regarded the plant as a new species of Sedum. Specimens later discovered in the area were unable to be distinguished from Hasseanthus blochmaniae (Blochman's dudleya). [4]

The genus Hasseanthus, now moved into a subgenus of Dudleya, includes plants characterized by a geophytic habit. A 1950 treatment of the plant by Reid Moran would then place it under the subspecies brevifolia of H. blochmaniae, noting some significant morphological differences. The genus Hasseanthus would later become a subgenera of Dudleya. [4]

By 1975, Moran's assessment of the species in the journal Baileya was more grim. Lamenting the "progress of civilization," he reconsidered it as a species in its own right, noting that the destruction of the introgressive populations that graded into Blochman's dudleya made these plants distinct enough to be deemed a species. [5]

With lichen, moss, and ironstone concretions, overlooking the Carmel Valley. DUDBRE6.jpg
With lichen, moss, and ironstone concretions, overlooking the Carmel Valley.

Hybridization

Two species of deciduous Dudleya graded into the population of Dudleya brevifolia. Hybrids with Dudleya edulis have also been reported. [7]

D. brevifolia × blochmaniae

One population approached Dudleya blochmaniae at a mesa east of La Jolla. The plants flowered three to four weeks earlier than the other populations of D. brevifolia, and had a different growth habit, being primarily found in depressions on the mesa. Compared to brevifolia, their rosettes and cauline leaves were slightly longer and narrower. The basal leaves and corms approached brevifolia. [9] Moran noted how it was difficult to distinguish brevifolia from blochmaniae until the advent of land development in the area extirpated the populations that transitioned between the two. [4] [5]

D. brevifolia × variegata

The plant was also known to grade into Dudleya variegata abundantly at a vernal pool-like depression north of Eastgate Mall road and west of the I-805 near Miramar and the Sorrento Valley. [10] [11] [3] The location is now an office park. [12] The hybrids possessed intermediate traits. [11] [13]

Distribution and habitat

Numerous plants, Carmel Mountain, San Diego. DUDBRE1.jpg
Numerous plants, Carmel Mountain, San Diego.

The plant is endemic to coastal sage scrub habitats in southern California, found only in an extremely limited range within southwestern San Diego County. [2] It is found at Torrey Pines State Natural Reserve in the La Jolla neighborhood of the City of San Diego, and several sites in Del Mar, both coastal communities within the county. [8] [14]

It is only found on bare surface hardpans of Torrey sandstone with minimal topsoil, from 30–250 metres (98–820 ft) in elevation. [8] Small marble-sized, ironstone concretions are present at all sites and are likely an edaphic requirement.

Ira L. Wiggins reported this species in his Flora of Baja California to be growing on sandstone bluffs and stony habitats along the coast of northwestern Baja California, [15] but no specimens have been found to corroborate this claim. [16]

Ecology

Phenology

As this plant is a geophyte, occupying a habitat consisting mostly of hardpan substrata, it has an unusual growth habit in which once the tuberous, underground stems hit the hardpan, they will then spread out horizontally along the surface of the impenetrable substrate. In areas with the most shallow soil that is still conducive to growth, this plant tends to have incredibly irregular stems. [17]

Annual growth begins after the first autumn rains, but this can be disturbed by any mid-winter drought conditions. If the plants are disturbed by any winter droughts, they will return to dormancy and wait until the next suitable growing season. This is most common in smaller plants, whilst larger plants will usually retain their leaves even through mid-winter droughts. This response may be mistaken for the death of plants, which are in fact dormant underground. [17]

Timing of rains may be more important than the quantity. Years with consistent and evenly spaced autumn-winter rains correlate with the most flowering individuals. Likewise, lack of precipitation in the middle of winter is associated with less plants flowering. In any given year, 10% to 30% of individuals will flower. This means that population estimates made from flowering plants may significantly undercount the number of individuals. [17]

Reproductive biology

This plant may reproduce through seed or via vegetative means. The vast majority of Dudleya species have difficulty in rooting from detached leaves, a trait that distinguished them from Echeveria in early taxonomic studies. In most rosette-forming evergreen Dudleya, the leaves will simply callous, wrinkle, and die. [18] However, some species, especially deciduous ones, may reproduce readily from detached leaves. One to three weeks after the leaves are detached from the plant, roots will emerge from the petiole base. [17]

Flowering at the edge of a mesa. DUDBRE5.jpg
Flowering at the edge of a mesa.

Seeds are typically dispersed by wind or water. The seeds are small, but are larger in comparison to other members of Dudleya, as plant size is inversely correlated with seed size. [19] The dried inflorescences may detach and tumble along the sandy mesas, which presumably may disperse seed. [17]

Many pollinators make visits to the flowers of D. brevifolia. These include bee flies (Bombyliidae), hover flies, soft-winged flower beetles ( Dasytes species, within the family Melyridae), western honey bees, bumble bees and digger bees (tribe Anthrophorini). [17]

Conservation

A population at Carmel Mountain, looking southwest to Torrey Pines. DUDBRE7.jpg
A population at Carmel Mountain, looking southwest to Torrey Pines.

The topography of coastal San Diego County is often challenging for urban development, with steep canyons shearing through flat mesas. The mesas, while suitable for development, were also an important location for vernal pools and other open habitats. Populations of deciduous Dudleya, like the variegated liveforever, Blochman's dudleya, and the many-stem dudleya, are resident to many of the vernal pools and clearings on top of these mesas, with the short-leaved dudleya representing a group localized to the bare surface hardpans of sandstone from Torrey Pines to La Jolla. [4] [5]

Their population is highly dependent on rainfall, exploding in population when there is annual rainfall over 10 inches, and drastically shrinking when there is less than 4 inches of annual rainfall. The species is seriously threatened by urbanization, vehicles, foot traffic, and fire break construction. [8]

Total population estimates vary by year and by the researcher. [20] Extensive studies have been completed on Carmel Mountain in the Carmel Valley community of San Diego. The Multiple Species Conservation Program (MSCP) of San Diego County estimated the Carmel Mountain population at just 1446 individuals in 2002, and at 113,134 individuals in 2006. [21] Most recently, in 2008, UCLA faculty Dr. Hartmut S. Walter and Matthew Luskin estimated the Carmel Mountain population at over 100,000 individuals. [8] [22]

Dudleya brevifolia is a high conservation priority because it exists only in these 5 locations (listed by decreasing average yearly population): Torrey Pines State Natural Reserve, Carmel Mountain (on multiple sites), Crest Canyon, Skeletal Canyon, and Torrey Pines Extension. The total habitat outside of the Torrey Pines State Natural Reserve that contains this species was estimated at just 2,667 square meters.

Endangered species

Dudleya brevifolia is currently listed as an endangered species by the state of California and by the California Native Plant Society. [14] [8]

Dudleya blochmaniae subsp. brevifolia was listed as an endangered species by the U.S. Fish and Wildlife Service in January 1982. In October 1996 they withdrew federal protection as an endangered species, citing the threats to the species had diminished and that it was a "covered species" within the Multiple Species Conservation Program (MSCP) of southern San Diego County. [23]

Related Research Articles

<i>Dudleya</i> North American succulent genus

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.

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

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.

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

Dudleya edulis is a species of perennial, succulent flowering plant of the Crassulaceae, known by the common names fingertips, lady-fingers, mission lettuce, or simply the San Diego dudleya. The common name "fingertips" denotes the finger-like shape of the leaves; the specific epithet edulis refers to the Kumeyaay people's traditional foraging and consumption of the plant's young scapes. Dudleya edulis is native to the dry, coastal cliffs and chaparral hills of Southern California and northern Baja California, where it has adapted to absorb as much moisture as possible from the nightly fog and marine layer which forms over the Pacific Ocean and gradually moves slightly inland, typically covering all plants and stationary objects in dew. In addition to its inherent drought-tolerance and xeric qualities, this species is also highly salt-tolerant, as it grows almost exclusively facing the ocean, often in exposed settings where it is subjected to regular periods of extreme wind and weather. The species may be found growing on rocky hillsides, sandstone sea cliffs, chaparral habitat, arid canyons, or rooted between exposed, bare rock crevices.

<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 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.

<i>Dudleya pulverulenta</i> Species of succulent plant found in the U.S. and Mexico

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 one of the most specialized inflorescences in the genus, adapted to hummingbird pollination through its red pendent flowers, the longest corolla, and the highest nectar output. Dudleya pulverulenta has the largest range of all 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. It is closely related to Dudleya arizonica, a smaller desert species that tends to lack the specialized floral traits, and Dudleya anthonyi, which differs in a few morphological traits and is restricted to the San Quintín Volcanic Field.

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

Dudleya stolonifera is a succulent plant known by the common name Laguna Beach liveforever or Laguna Beach dudleya. This is a rare plant which is endemic to the coastline of Orange County, California. It is known from only about six populations in the vicinity of Laguna Beach, totaling about 30,000 individuals. It is federally listed as a threatened species of the United States.

<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 variegata</i> Species of succulent

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.

<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. It is a rosette-forming leaf succulent which 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 hendrixii</i> Species of succulent

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.

<i>Dudleya guadalupensis</i> Species of succulent plant from Mexico

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 anomala</i> Species of plant

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.

<i>Dudleya nubigena</i> Species of succulent plant from Mexico

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.

<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> 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 crassifolia</i> Species of succulent plant from Mexico

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.

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

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.

<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.

Dudleya virens subsp. extima is a subspecies of succulent plant in the family Crassulaceae commonly known as the Guadalupe green liveforever. It is a rosette-forming leaf succulent, with both green and white waxy foliage. It has white flowers with spreading petals that bloom from May to June. It is a somewhat small plant, continuing a southward trend of decreasing size relative to other Dudleya virens subspecies. This plant is endemic to Guadalupe Island in the eastern Pacific Ocean, which is 241 kilometers off of the Baja California coast. It is very rare, with this plant only surviving on sheer cliff faces and canyons, out of the reach of the former feral goat population rampant on the island. It closely resembles a miniature version of Dudleya virens subsp. virens, but it may be more nearly related to the local Dudleya guadalupensis.

References

  1. 1 2 3 4 Jepson eFlora: Dudleya brevifolia . accessed 4 July 2016.
  2. 1 2 3 4 Calflora: Dudleya brevifolia . accessed 4 July 2016.
  3. 1 2 Beauchamp, R. Mitchel (1986). A Flora of San Diego County, California. National City, California: Sweetwater River Press. p. 146. ISBN   0-931950-01-5.
  4. 1 2 3 4 5 Moran, Reid Venable (1950). "Hasseanthus blochmaniae ssp. brevifolius". Desert Plant Life. 22: 80–82.
  5. 1 2 3 4 Moran, Reid Venable (1975). "Dudleya brevifolia". Baileya . 19: 146.
  6. ↑ Davitt, Joe (22 February 2022). "Release the Dudleya! Part 1". science.sandiegozoo.org. San Diego Zoo Wildlife Alliance. Retrieved 13 February 2022.
  7. 1 2 3 4 5 Moran, Reid. "Dudleya brevifolia". In Flora of North America Editorial Committee (ed.). Flora of North America North of Mexico (FNA). New York and Oxford: Oxford University Press. Retrieved 10 February 2022– via eFloras.org, Missouri Botanical Garden, St. Louis, MO & Harvard University Herbaria, Cambridge, MA.
  8. 1 2 3 4 5 6 California Native Plant Society: Inventory of Rare and Endangered Plants (online edition, v8-02) report on Dudleya brevifolia . accessed 4 July 2016.
  9. ↑ Moran, Reid (May 1945). "Notes on Hasseanthus — I". Desert Plant Life. 17: 69–83.
  10. ↑ Oberbauer, Tom (May 19, 1979). "SD104294". CCH1. Archived from the original on 2021-10-06.
  11. 1 2 Nakai, K (31 March 1982). "Dudleya brevifolia (Moran) Moran". California Academy of Sciences. Archived from the original on 2014-10-28.
  12. ↑ University Community Plan (PDF). The University Community Planning Group and City of San Diego Planning Department. 2019. pp. 110–111.
  13. ↑ Reiser, Craig H. (July 2001). Rare Plants of San Diego County (PDF). Aquafir Press. pp. 104–105. ASIN   B0006F4BAY.
  14. 1 2 DFG.ca.gov: Dudleya blochmaniae subsp. brevifolia / Dudleya brevifolia [ permanent dead link ]
  15. ↑ Wiggins, Ira L. (1980). Flora of Baja California. Stanford, Calif.: Stanford University Press. p. 633. ISBN   0-8047-1016-3. OCLC   6284257.
  16. ↑ Rebman, Jon P.; Gibson, Judy; Rich, Karen (15 November 2016). "Annotated Checklist of the Vascular Plants of Baja California, Mexico" (PDF). Proceedings of the San Diego Society of Natural History. 45. San Diego Natural History Museum: 325 – via San Diego Plant Atlas & San Diego Natural History Museum.
  17. 1 2 3 4 5 6 Dodero, Mark; Stephenson, Bobbie (April 2005). "Short-leaved Dudleya Enhancement and Restoration Plan for the Carmel Mountain Preserve, San Diego, California". Carmel Mountain and del Mar Mesa RMP. RECON – via sandiego.gov.
  18. ↑ Thomson, Paul H. (1993). Dudleya and Hasseanthus Handbook. Bonsall Publications. ISBN   978-0960206650.
  19. ↑ Amoroso, D. M., & Wilson, P. (2018). Ten Cases of Divergence in the Seedling Ecology of Dudleya (Crassulaceae). Systematic Botany, 43(4), 889-900.
  20. ↑ USGS.gov: Dudleya blochmaniae subsp. brevifolia
  21. ↑ "Sandiego.gov: Dudleya blochmaniae subsp. brevifolia monitoring" (PDF). Archived from the original (PDF) on 2011-05-16. Retrieved 2008-03-07.
  22. ↑ California Native Plant Society, Inventory of Rare and Endangered Plants of California (2001) report of Rare Plant Scientific Advisory Committee, California Native Plant Society. Sacramento, CA. Data tables from electronic copy of the Inventory.
  23. ↑ US-FWS.gov: Dudleya blochmaniae subsp. brevifolia (Endangered species)
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