Dudleya guadalupensis

Dudleya guadalupensis
	Plant with inflorescence (top) and flower (bottom)
Scientific classification
Kingdom:	Plantae
Clade:	Tracheophytes
Clade:	Angiosperms
Clade:	Eudicots
Order:	Saxifragales
Family:	Crassulaceae
Genus:	Dudleya
Species:	D. guadalupensis
Binomial name
	Dudleya guadalupensis; Moran

Last updated February 17, 2022

Dudleya guadalupensis is a very rare species of succulent perennial plant in the family Crassulaceae commonly known as the Guadalupe liveforever.^[1] 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.^[2]^[3] 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.^[1]

Description

A densely-leaved species of Dudleya, with the outer foliage folding over the center, giving the rosettes a rounded appearance. It has a curved flower stalk and white flowers that form a cup or "V" shape.^[3]

Morphology

Like most other Dudleya, this plant is a rosette-forming leaf succulent which grows rosettes on the tips of a stem, with the stem also referred to as a caudex. In this species, the caudex is 1.5 to 3.5 cm (0.59 to 1.38 in) thick, and elongates up to 15 cm (5.9 in) or more long, the caudex branching to form rounded clumps up to 50 cm (20 in) wide, of up to 80 or more rosettes. The rosettes are almost globe-shaped, 3–15 cm (1.2–5.9 in) wide, of 24–40 leaves, with the leaves colored a pale green, green, or white with epicuticular wax. The leaves are shaped oblong to oblanceolate, the leaf margins rounded, and the tip apiculate to acuminate. Each leaf is typically 2.5–6.5 cm (0.98–2.56 in) long, 8–13 mm (0.31–0.51 in) wide, 2–3 mm (0.079–0.118 in) thick, and 4–8 mm (0.16–0.31 in) at the base.^[2]^[4]

The floral stems of this species are characterized by an unusual sinuous habit, in that they curve downward at first, and then curve up. The floral stems are glaucous, 20–30 cm (7.9–11.8 in) long and 4–7 mm (0.16–0.28 in) thick. The floral stem is bare of bracts in the lower 5 cm (2.0 in), but above that has 15–35 bracts. The bracts themselves are shaped triangular-ovate, with an acute tip, and with a glaucous surface. The lowermost bracts measure 1–2 cm (0.39–0.79 in) long, and 7–10 mm (0.28–0.39 in) wide. The cyme is glaucous, and consists of 2-3 ascending simple or bifurcated branches, with the terminal branches 4–8 cm (1.6–3.1 in) long, containing 7–12 flowers held on pedicels. The pedicels are erect, with the lower ones 3–5 mm (0.12–0.20 in) long and the upper ones 2–3 mm (0.079–0.118 in) long.^[2]^[4]

The flowers have a calyx 5–6 mm (0.20–0.24 in) wide, and 6–8 mm (0.24–0.31 in) high, rounded below, with the tube 1–1.5 mm (0.039–0.059 in) long. The calyx segments are narrowly triangular-ovate, and are 3–5 mm (0.12–0.20 in) long by 2.5–3.5 mm (0.098–0.138 in) wide. The corolla is a pale greenish yellow, but it has a glaucous surface texture that makes it appear almost white, with it being 11–13 mm (0.43–0.51 in) long, and around 4 mm (0.16 in) wide at the base and 7–11 mm (0.28–0.43 in) wide above. The petals are shaped linear to lanceolate, with an acute tip, 2–2.5 mm (0.079–0.098 in) wide, connate 1–2 mm (0.039–0.079 in). The petals are strongly keeled, nearly straight, positioned erect to ascending but not touching much above the calyx.^[2]^[4]

The plant is said to bear a superficial resemblance to Dudleya linearis , native to San Benito Island.^[4]

Taxonomy

Taxonomic history

In 1892, Dr. Francescho Franceschi, a horticulturist from Santa Barbara, visited Guadalupe Island. He published an account of the trip and the plants he found, and among them, he reported a " Cotyledon sp." on a rock by a trail not far from the landing.^[5] No other expeditions found or mentioned Dudleya until 1948,^[4] when Reid Moran and George Lindsay visited the island. The island had been decimated by feral goats that had been introduced by European sailors, which caused significant damage to the flora and left many plants only extant in areas where the goats could not reach. On the far northern portion of the island, where the Guadalupe pine grows, Moran and Lindsay found a clump of Dudleya growing on a north-facing cliff around 3,500 ft (1,100 m) above the sea, out of reach of the goats. Moran noted this plant's similarity to the Dudleya caespitosa found on the Californian coast, and the species on the northern end of Guadalupe would later be recognized as Dudleya virens subsp. extima.^[5]

The second population of Dudleya was discovered by Moran and Lindsay on Islote Afuera, a small islet off the southern coast of Guadalupe. The small islet is a volcanic cone with sheer vertical cliffs surrounded by tidal currents, but on the north side of the crater there is a small cove and a scalable slope. After failing to reach the islet with a skiff due to the dangerous conditions, Moran and Lindsay finally reached the cove with a rubber life raft, although they left their cameras behind due to the sheer danger of the landing. After overcoming the dangerous landing, Moran and Lindsay discovered what they regarded as the most interesting plant on the island, a species of Dudleya. Unlike the other plants on the northern end of the island, the plants on the islet had unusually dense green rosettes, with two different sizes of leaves. Another unusual feature was the twisting floral stem, which was present on all the plants. The peduncle is sinuously twisted, on both immature and dried inflorescences. After only one hour and a half of botanical work, Moran and Lindsay had to return to their ship, the Marviento, after the captain fired his gun to signal their return.^[5]

In 1955, George Lindsay supposedly saw plants on the rocks off of the north end of the island. In 1957, Reid Moran returned to Guadalupe Island, and found the typical green form of this species on Islote Negro, but also a white form covered in epicuticular wax. On Islote Negro, the plants occur occasionally, with the rosettes not as clustered but typically solitary or few, although some still formed clusters 40 cm wide. In August 1970, Moran also spotted this plant on Middle Rock.^[2]

In June of 2000, a team of Mexican and American botanists discovered this species on Islote de Adentro (or Islote Toro).^[6]

Phylogeny

Chromosome counts of the plants collected by Reid Moran on Islote Afuera and Islote Negro done by Dr. Charles H. Uhl indicate that all collections of the plant are diploid relative to the basic number for the genus, with a chromosome count of n = 17.

A 1985 paper alleged that a Dudleya of this species from Guadalupe Island had a chromosome count of 2n = 102,^[7] but Moran cast doubt on the author's specimens, as the authors failed to list a herbarium record. It is likely that the authors of the 1985 paper acquired the plant as a mislabeled Dudleya greenei , which is often mistakenly sold as Dudleya guadalupensis. The hypothesis that the authors of the 1985 paper got their plant as a mislabeled Dudleya greenei is further evidenced by the fact that greenei has a chromosome count of n = 51, which corresponds to the somatic count of 2n = 102.^[2]

Phylogenetic analyses have placed this species as sister to Dudleya virens subsp. extima, which occurs on the northern end of Guadalupe Island.^[8]

Distribution and habitat

Dudleya guadalupensis is native to Guadalupe Island and the surrounding islets. The type specimen originates from Islote Afuera (Outer Islet), collected by Reid Moran.^[4] On Islote Afuera, the plants are common from the inner slope of the crater to the upper valley. The plants there have uniformly light green foliage. On Islote Negro, plants have both green and farinose foliage, with the rosettes being less clustered and more solitary. The species is present on Islote Adentro (Islote Toro).^[6] Plants have also been spotted on Middle Rock and other islets off of the island.^[2]

Cultivation

Most of the examples of plants alleged to be this species in cultivation may be mislabeled. Noted Dudleya collector Paul Thomson observed that many of the plants in cultivation bear little resemble to actual D. guadalupensis plants.^[3] Reid Moran also notes that plants in the nursery trade labeled as D. guadalupensis are in fact D. greenei , a species native to the Channel Islands of California with a different chromosome count. Moran found that none of the collectors of the cultivated specimens could verify that the source was from Guadalupe Island.^[2]

Related Research Articles

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 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 is not immediately separable from the other species it approaches.

Dudleya candelabrum is a succulent plant known by the common name Candleholder liveforever. This Dudleya is endemic to California, where it grows wild only on the northern Channel Islands. It has been threatened by poachers shipping plants to South Korea.

Dudleya palmeri is a species of succulent plant in the family Crassulaceae known by the common name Palmer's liveforever. This Dudleya is endemic to California where it grows along the coast. It is characterized by orange to red over yellow or pink flowers. It is a polyploid species that closely resembles Dudleya lanceolata but has a coastal habit, and hybridizes with Dudleya caespitosa and Dudleya cymosa.

Dudleya traskiae is a rare succulent plant known by the common name Santa Barbara Island liveforever. This Dudleya is endemic to Santa Barbara Island, one of the Channel Islands of California, where it grows on rocky bluffs. The plant has a basal rosette of flat, spade-shaped fleshy leaves up to 15 centimeters long, which are pale green to yellowish. It erects tall stems bearing dense, rounded inflorescences of many bright yellow flowers.

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.

<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.

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 endemic to Santa Rosa Island, one of the Channel Islands of California, where it is known from one type locality containing about 3200 plants.

Dudleya attenuata, known by common name as the taper-tip liveforever, is a species of perennial succulent plant native to Baja California and a small portion of California. It is a diverse, polymorphic and frequently hybridizing species that extends from the southernmost coast of San Diego County to an area slightly north of the Vizcaino Desert. Some plants with varying flowers are referred to as Orcutt's liveforever.

Dudleya rigida is a species of succulent perennial plant in the family Crassulaceae known commonly as the La Laguna liveforever. Characterized by a tall inflorescence with pendant yellowish-red flowers, it is a very rare plant whose existence was doubtful until botanist Reid Moran accidentally re-discovered it. It is endemic to the Sierra de la Laguna in Baja California Sur, 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.

Dudleya formosa, known by the common name La Misión liveforever, is a species of perennial succulent plant endemic to the Guadalupe Valley in Baja California. It is characterized by bright green leaves, red floral stems, and pink flowers.

Dudleya rigidiflora is a very rare species of succulent perennial plant known by the common name Playa Maria liveforever, endemic to the coast of southwestern Baja California.

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, and on Cerralvo Island.

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."

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 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.

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.

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 species is endemic to Guadalupe Island in the eastern Pacific Ocean, which is 241 kilometers off of the Baja California coast. It is a very rare species, 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 2 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.
1 2 3 4 5 6 7 8 Moran, Reid (1996). The Flora of Guadalupe Island. California Academy of Sciences. pp. 98–100. ISBN 0-940228-40-8.
1 2 3 Thomson, Paul H. (1993). Dudleya and Hasseanthus Handbook. Bonsall, California: Bonsall Publications. p. 77. ISBN 9780960206650.
1 2 3 4 5 6 Moran, Reid (1951). "Notes on the Flora of Guadalupe Island, Mexico". Madroño. California Botanical Society. 11: 153–160 – via JSTOR.
1 2 3 Moran, Reid; Lindsay, George (January 1950). "Guadalupe Island". Desert Plant Life. 22: 3–9 – via archive.org.
1 2 Rebman, Jon P.; Oberbauer, Thomas A.; de la Luz, José Luis León (2002). "THE FLORA OF TORO ISLET AND NOTES ON GUADALUPE ISLAND, BAJA CALIFORNIA, MEXICO". Madroño. 49 (3): 145–149. ISSN 0024-9637.
↑ Funamoto, Tsuneo; Yuasa, Hiroshi; Kondo, Norio (1985-01-01). "Chromosome study on six species of the genus Dudleya (Crassulaceae)". Chromosome Information Service. 38: 32–34.
↑ Yost, Jenn M.; Bontrager, Megan; McCabe, Stephen Ward; Burton, Darren; Simpson, Michael G.; Kay, Kathleen M.; Ritter, Matt (2013-12-01). "Phylogenetic Relationships and Evolution in Dudleya (Crassulaceae)". Systematic Botany. 38 (4): 1096–1104. doi:10.1600/036364413X674760. S2CID 15715233. Dudleya virens subsp. insularis (Rose) Moran and D. v. subsp. virens (Rose) Moran are strongly supported as sister taxa (1.0 BI PP; Fig. 1) but are not allied with D. v. subsp. extima Moran. Instead, D. guadalupensis Moran and D. v. subsp. extima are strongly supported as sister taxa (1.00 BI PP; Fig. 1).The same relationship is recovered in the nrDNA tree (Fig. 2).The cpDNA tree shows moderate support (0.88 BI PP)for a paraphyletic D. virens, with D. guadalupens is embedded within D. virens (Fig. 3).

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[rebman-1] 1 2 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.

[Moran1996-2] 1 2 3 4 5 6 7 8 Moran, Reid (1996). The Flora of Guadalupe Island. California Academy of Sciences. pp. 98–100. ISBN 0-940228-40-8.

[Thomson1993-3] 1 2 3 Thomson, Paul H. (1993). Dudleya and Hasseanthus Handbook. Bonsall, California: Bonsall Publications. p. 77. ISBN 9780960206650.

[Moran1951Notes-4] 1 2 3 4 5 6 Moran, Reid (1951). "Notes on the Flora of Guadalupe Island, Mexico". Madroño. California Botanical Society. 11: 153–160 – via JSTOR.

[LindsayMoran1950-5] 1 2 3 Moran, Reid; Lindsay, George (January 1950). "Guadalupe Island". Desert Plant Life. 22: 3–9 – via archive.org.

[ToroExpedition2000-6] 1 2 Rebman, Jon P.; Oberbauer, Thomas A.; de la Luz, José Luis León (2002). "THE FLORA OF TORO ISLET AND NOTES ON GUADALUPE ISLAND, BAJA CALIFORNIA, MEXICO". Madroño. 49 (3): 145–149. ISSN 0024-9637.

[7] Funamoto, Tsuneo; Yuasa, Hiroshi; Kondo, Norio (1985-01-01). "Chromosome study on six species of the genus Dudleya (Crassulaceae)". Chromosome Information Service. 38: 32–34.

[Yost-8] Yost, Jenn M.; Bontrager, Megan; McCabe, Stephen Ward; Burton, Darren; Simpson, Michael G.; Kay, Kathleen M.; Ritter, Matt (2013-12-01). "Phylogenetic Relationships and Evolution in Dudleya (Crassulaceae)". Systematic Botany. 38 (4): 1096–1104. doi:10.1600/036364413X674760. S2CID 15715233. Dudleya virens subsp. insularis (Rose) Moran and D. v. subsp. virens (Rose) Moran are strongly supported as sister taxa (1.0 BI PP; Fig. 1) but are not allied with D. v. subsp. extima Moran. Instead, D. guadalupensis Moran and D. v. subsp. extima are strongly supported as sister taxa (1.00 BI PP; Fig. 1).The same relationship is recovered in the nrDNA tree (Fig. 2).The cpDNA tree shows moderate support (0.88 BI PP)for a paraphyletic D. virens, with D. guadalupens is embedded within D. virens (Fig. 3).

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