Dudleya linearis is an insular succulent plant known by common name as the San Benitos liveforever. It is a rosette-forming perennial characterized by its long, flat green leaves on clustered heads and its yellow flowers. It is endemic to the western island of the Islas San Benito, a small Mexican archipelago in the Pacific Ocean west of Cedros Island. The limited population of the species is vulnerable, and has twice come close to extinction from introductions of grazing animals.
Dudleya linearis is a succulent perennial with long, flat green leaves in clustered rosettes and distinctive yellow flowers from March to May. The chromosome number is n=17, the base number for Dudleya.
Reid Moran noted that Dudleya linearis closely resembles, in vegetative form, Dudleya guadalupensis, endemic to Guadalupe Island to the northwest, based on their long, flat green leaves. The two can be separated by their significantly different inflorescences and flowers. Plants of Dudleya albiflora on Cedros Island have also been historically confused with this species.
The caudices are caespitose, branching apically. They measure 1âÂÂ2 cm in thickness. The branched caudices give the plants a cluster of 10 to 20 rosettes, which measure 2âÂÂ5 cm in diameter. The rosettes have 20âÂÂ40 leaves. The leaves are oriented in a erect or somewhat spreading manner. The leaves are light green and not glaucous. They measure 2.5âÂÂ6 cm long by 5âÂÂ10 mm wide and 2âÂÂ3 mm thick. The leaf base is 5âÂÂ8 mm wide. The leaf shape is linear or oblong to oblong-oblanceolate, and the tip is acuminate to sharply acute.
The peduncle is 6âÂÂ17 cm tall and is 1.5âÂÂ2 mm thick. The inflorescence is glaucous and compact, and is composed of 2 to 3 simple branches. The terminal branches (cincinni) measure 2âÂÂ5 cm long and are ascending. The cincinni bear 2âÂÂ10 flowers, borne on erect pedicels, the lowermost pedicels 2âÂÂ6 mm long. There are only 5âÂÂ8 bracts on the peduncle, the lower two-thirds or lower third being absent of them. The bracts have an ascending orientation, and are shaped lanceolate with an acute apex. The lowermost bracts measure 5âÂÂ20 mm long by 2âÂÂ9 mm wide and are usually in a subopposite arrangement.
The calyx measure 3âÂÂ4.5 mm wide by 4âÂÂ6 mm high. The sepals are 2.5âÂÂ4 mm long and are shaped triangular-lanceolate. The petals are 7âÂÂ12 mm long and 2.5 mm wide, and are connate for 1.5âÂÂ2.5 mm. The petals are yellow. The carpels are erect and appressed.
Dudleya linearis was discovered on West San Benito Island by Lieutenant C.F. Pond, and described by Edward Lee Greene in 1889 as Cotyledon linearis in Pittonia.
In 1903, the botanists Nathaniel Lord Britton and Joseph Nelson Rose created the new genus Dudleya, named in honor of William Russel Dudley, which absorbed most of the Cotyledon species described in California and the Baja California Peninsula under the new genus, creating the combination Dudleya linearis.
In 1930, Alwin Berger, who worked within the Engler system of plant taxonomy, recombined a number of the new species created by Britton and Rose into Echeveria, creating the combination Echeveria linearis.
Dudleya linearis is endemic to West San Benito Island, the largest of the San Benito Islands, an archipelago west of Cedros Island. It is somewhat scarce, and is found on canyon walls and slopes on the north side of the island. The plant is not present on the eastern or middle islands.
West San Benito is home to a small community of fishermen, up to 70 seasonally, who live in a settlement on the east side of the island.
When botanist Reid Moran visited the island in 1948, he was only able to find a few living plants and large numbers of dead ones, with only 3 flowering plants that year. Donkeys had been introduced to West San Benito as pack animals, and brought D. linearis close to extinction. Small groups of feral donkeys were still seen on the island from 1975âÂÂ1992. The donkey population is now corralled and fed imported food, posing little threat to the Dudleya.
In 1990s, rabbits and goats were brought to island, possibly by the lighthouse keeper or fishermen. The rabbits devastated the population of D. linearis, nearly to the point of extirpation. In 1998, conservation groups and the Mexican government started a program to remove rabbits and goats from the island. A hunter with his Jack Russell Terrier named "Freckles" was hired to eliminate the rabbits. Over 400 rabbits were hunted or trapped over a 7 month period. The elimination of the rabbits and goats, along with an El Niño year, led to the rebound of the D. linearis population.