''Dudleya densiflora'' is a species of succulent plant in the family

Crassulaceae The Crassulaceae (from Latin ''crassus'', thick), also known as the stonecrop family or the orpine family, are a diverse family of dicotyledon flowering plants characterized by succulent leaves and a unique form of photosynthesis, known as Crass ...

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.

Description

A clumping plant with long, pencil-shaped and powdery leaves, with a branching, rounded inflorescence that holds spreading, white to pink flowers. The flowers emerge from spring to June. It is similar in appearance to ''

Dudleya edulis ''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 '' ...

'' and '' Dudleya viscida'', but differs in having white powdery leaves and a rounded, not flat-topped,

inflorescence An inflorescence is a group or cluster of flowers arranged on a Plant stem, stem that is composed of a main branch or a complicated arrangement of branches. Morphology (biology), Morphologically, it is the modified part of the shoot of sperma ...

Morphology

This plant grows in a caespitose or clumping habit, with multiple rosettes of leaves forming on top of branching

caudices A caudex (plural: caudices) of a plant is a stem, but the term is also used to mean a rootstock and particularly a basal stem structure from which new growth arises.pages 456 and 695 In the strict sense of the term, meaning a stem, "caudex" is ...

. The caudex is wide. The clumps of rosettes may reach up to in diameter, and have a foliage consisting of 20 to 40 leaves. The

evergreen In botany, an evergreen is a plant which has foliage that remains green and functional through more than one growing season. This also pertains to plants that retain their foliage only in warm climates, and contrasts with deciduous plants, whic ...

foliage is covered in a white, waxy powder, known as an

epicuticular wax Epicuticular wax is a coating of wax covering the outer surface of the plant cuticle in land plants. It may form a whitish film or bloom on leaves, fruits and other plant organs. Chemically, it consists of hydrophobic organic compounds, mainly st ...

, with the leaf blades green underneath the substance. The base of the leaf may turn a yellow when the leaf is wounded. Each leaf is long by wide, more or less cylindric, with a linear shape. The tip of the leaf is shaped acute. The peduncle is tall, and wide. The floral shoots are covered in 5 to 15 bracts, which are erect and shaped lanceolate. The inflorescence branches 3 to several times, with each branch sometimes dividing into one or two more terminal branches. The terminal branches are long and bear 2 to 8 flowers, suspended on

pedicels In botany, a pedicel is a stem that attaches a single flower to the inflorescence. Such inflorescences are described as ''pedicellate''. Description Pedicel refers to a structure connecting a single flower to its inflorescence. In the absenc ...

long. The flowers are spreading from the middle, the

sepal A sepal () is a part of the flower of angiosperms (flowering plants). Usually green, sepals typically function as protection for the flower in bud, and often as support for the petals when in bloom., p. 106 The term ''sepalum'' was coine ...

s shaped deltate to ovate. The petals are long, with a narrowly ovate shape, and are colored a white or pink. The entire corolla is around in diameter.

Distribution and habitat

This species is restricted to a small locality in

southern California Southern California (commonly shortened to SoCal) is a geographic and cultural region that generally comprises the southern portion of the U.S. state of California. It includes the Los Angeles metropolitan area, the second most populous urban a ...

, in the

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territori ...

. It is found growing at the southern base of the San Gabriel Mountains, in an area near the mouth of San Gabriel Canyon and Fish Canyon. The habitat of this species consists of sheer rock faces, cliffs, and canyon walls, usually composed of granitic rock. ''Dudleya densiflora'' is threatened by human activity encroaching on its habitat. A notable disturbance is the presence of a granite quarry operating for the community of

Azusa Azusa may refer to: Relating to California From a Native American language, likely Tongva language, Tongva ''Asuksagna:'' *Azusa, California, a city in the United States *Azusa Pacific University, a Christian-based institution in Azusa, California ...

, with the permit for the quarry issued in 1956, before most environmental laws existed. The quarry also blocks the entrance to Fish Canyon, which was formerly accessible as a trail maintained by the Forest Service. In Fish Canyon, this species can also be found growing with another ''Dudleya'' endemic to the locality, ''Dudleya cymosa'' subsp. ''crebrifolia''.

Gallery

File:Dudleya densiflora 174645895.jpg, A young plant growing on a rocky face File:Dudleya densiflora 174646103.jpg, A plant with a single rosette, growing on moss File:San Gabriel Mountains dudleya imported from iNaturalist photo 2825459 on 21 December 2021.jpg, A large clump of a plant File:Dudleya densiflora 174645939.jpg, Growing out of a cliff face File:San Gabriel Mountains dudleya imported from iNaturalist photo 2825460 on 21 December 2021.jpg, Growing in habitat

References

External links