''Dudleya abramsii'' subsp. ''setchellii'', known by common name as the Santa Clara Valley dudleya or Santa Clara Valley liveforever, is a member of the ''

Dudleya ''Dudleya'', commonly known as liveforevers (Spanish: ''siemprevivas'') is a genus of succulent plants in the stonecrop family, Crassulaceae, consisting of about 68 taxa in southwestern North America and Guadalupe Island. The species come in mul ...

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

succulent In botany, succulent plants, also known as succulents, are plants with parts that are thickened, fleshy, and engorged, usually to retain water in arid climates or soil conditions. The word ''succulent'' comes from the Latin word ''sucus'', meani ...

perennials, members of 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 ...

. The Santa Clara Valley dudleya,

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

to the

Santa Clara Valley The Santa Clara Valley is a geologic trough in Northern California that extends 90 miles (145 km) south–southeast from San Francisco to Hollister. The longitudinal valley is bordered on the west by the Santa Cruz Mountains and on the east ...

region in the southern

San Francisco Bay Area The San Francisco Bay Area, often referred to as simply the Bay Area, is a populous region surrounding the San Francisco, San Pablo, and Suisun Bay estuaries in Northern California. The Bay Area is defined by the Association of Bay Area Go ...

, was listed on 3 February 1995, as an

endangered species An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching and inv ...

. It is considered to be a subspecies of ''

Dudleya abramsii ''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 smal ...

,'' but its taxonomic status is still unclear. Its closest relative is ''Dudleya cymosa'' subsp. ''paniculata'', which is a morphologically similar sister taxon.''''

Description

A perennial rosette-forming succulent, this species is characterized by pale yellow petals, a simple (not branching multiple times) inflorescence, and a restriction to serpentine soil.

Morphology

This rosettes are anywhere from wide, on top of stems (also referred to as

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 ...

) that are wide. The stems may branch dichotomously to form 1 to 5 rosettes. The leaves are shaped oblong-triangular to lance-elliptic to lanceolate, and have a

glaucous ''Glaucous'' (, ) is used to describe the pale grey or bluish-green appearance of the surfaces of some plants, as well as in the names of birds, such as the glaucous gull (''Larus hyperboreus''), glaucous-winged gull (''Larus glaucescens''), g ...

surface. The leaves measure long by wide. The peduncle is tall and wide. The lower

bract In botany, a bract is a modified or specialized leaf, especially one associated with a reproductive structure such as a flower, inflorescence axis or cone scale. Bracts are usually different from foliage leaves. They may be smaller, larger, or of ...

s on the peduncle measure long. There are typically 2 to 3 first degree branches on the

inflorescence An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Morphologically, it is the modified part of the shoot of seed plants where flowers are formed o ...

, which are oriented in an ascending fashion and usually do not bifurcate further. On the branches are

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 ...

, measuring in length, holding the flowers. The flowers have

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 coined b ...

s that are long, and shaped deltate. The

petal Petals are modified Leaf, leaves that surround the reproductive parts of flowers. They are often advertising coloration, brightly colored or unusually shaped to attract pollinators. All of the petals of a flower are collectively known as the ''c ...

s are long by wide, and shaped elliptic, with their tips acute. The lower parts of the petals are fused the way up to form a tube. The petals are colored a pale yellow.

Taxonomy

''Dudleya abramsii'' subsp. ''setchellii'' has undergone numerous changes in its taxonomic classification. Originally placed a subspecies of ''

Cotyledon A cotyledon (; ; ; , gen. (), ) is a significant part of the embryo within the seed of a plant, and is defined as "the embryonic leaf in seed-bearing plants, one or more of which are the first to appear from a germinating seed." The numb ...

laxa'' / ''

Echeveria ''Echeveria'' is a large genus of flowering plants in the family Crassulaceae, native to semi-desert areas of Central America, Mexico and northwestern South America. Description Plants may be evergreen or deciduous. Flowers on short stalks (cyme ...

laxa'', an antiquated synonym for ''

Dudleya caespitosa ''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, ...

'', botanists

Nathaniel Lord Britton Nathaniel Lord Britton (January 15, 1859 – June 25, 1934) was an American botanist and taxonomist who co-founded the New York Botanical Garden in the Bronx, New York (state), New York. Early life Britton was born in New Dorp, Staten Island, New ...

and

Joseph Nelson Rose Joseph Nelson Rose (January 11, 1862 – May 4, 1928) was an American botanist. He was born in Union County, Indiana. His father died serving during the Civil War when Joseph Rose was a young boy. He later graduated from high school in Liberty, ...

placed it as a separate species within Dudleya in 1903. In a 1957 issue of Madroño, botanist Reid Moran revised ''setchellii'' as a subspecies of ''

Dudleya cymosa ''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 ...

''. ''Cotyledon'' ''caespitosa'' var. ''paniculata'', now ''Dudleya'' ''cymosa'' subsp. ''paniculata'', was merged into ''setchellii''. Almost half a century later, Moran and other botanists returned to ''setchellii'', and again revised it as a subspecies of ''Dudleya abramsii.'' It is visually similar to and sometimes indistinguishable from ''Dudleya cymosa'' subsp. ''paniculata''. Recent

phylogenetic In biology, phylogenetics (; from Greek φυλή/ φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary history and relationships among or within groups o ...

analysis may in fact place ''setchellii'' back into a subspecies of ''D. cymosa'', as it is most closely related to ''D. c.'' subsp. ''paniculata''. Reid Moran, who combined it back into ''D. abramsii'', suggests that it owes a superficial resemblance to ''Dudleya abramsii'' subsp. ''murina''. Dudleya setchellii (15390385109)

Distribution

''Dudleya abramsii'' subsp. ''setchellii'' is found only in the Coyote Valley area of southern

Santa Clara County, California Santa Clara County, officially the County of Santa Clara, is the sixth-most populous county in the U.S. state of California, with a population of 1,936,259, as of the 2020 United States Census, 2020 census. Santa Clara County and neighboring Sa ...

, mostly on rocky outcrops within serpentine grasslands on Tulare Hill and the

Santa Teresa Hills The Santa Teresa Hills are a range of mountains in Santa Clara County, California, located primarily in the city of San Jose. They separate the San Jose neighborhoods of Almaden Valley to the west and Santa Teresa to the east. Geography The ra ...

west of Coyote Creek in south San Jose and south of Metcalf Canyon east of Coyote Creek.

Gallery

File:Dudleya abramsii setchellii 74620648.jpg, Detail of the flowers and inflorescence in bloom File:Dudleya abramsii setchellii 74362856.jpg, Detail of the flowers and inflorescence in bloom File:Dudleya abramsii setchellii 18104818.jpg, Detail of the flowers and inflorescence in bloom File:SC Valley Dudleya 4 (16750380870).jpg, Growing in habitat File:SC Valley Dudleya 2 (16937824965).jpg, Plants in habitat

References

External links

Jepson Manual Treatment – ''Dudleya setchellii''USDA Plants Profile: ''Dudleya setchellii''''Dudleya setchellii'' – Photo gallery
{{Taxonbar, from=Q5312064 abramsii setchellii Endemic flora of California Natural history of the California chaparral and woodlands Natural history of Santa Clara County, California Taxa named by Willis Linn Jepson Endemic flora of the San Francisco Bay Area Taxa named by Reid Venable Moran