Dudleya Verityi

''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.California Native Plant Society, Rare Plant Program. 2018. Inventory of Rare and Endangered Plants of California (online edition, v8-03 0.39). Website http://www.rareplants.cnps.org accessed 20 July 2018. It probably occurs in a few additional locations nearby which have not yet been officially vouchered.USFWS
''Dudleya verityi'' Five-year Review.
August 17, 2009.

Description

This is a fleshy perennial plant growing from a branching caudex several centimeters long. The leaves appear in a basal rosette about the caudex. The leaves are waxy in texture, pale grayish or pinkish green in color. The erect inflorescence is composed of a bract-lined peduncle up to 15 centimeters tall which splits into terminal branches each bearing several flowers. The flower has a base of fleshy, triangular sepals and longer, bright yellow petals just over a centimeter long.

Vegetative morphology

The caudex is 2 to 10 mm thick, and 2 to 10 cm long, and caespitosely branches to form a relaxed cluster, which may be more tightly compact in cultivation. The cluster is roughly 10 to 40 cm wide, with 25 to 100 or more rosettes. Each rosette is around 2 to 8 cm in diameter, with 6 to 10 leaves. The rosette leaves are glaucous, shaped oblong to lanceolate, and have a leaf apex shaped acute to acuminate. The leaves are roughly 2 to 5 cm long, 4 to 8 mm wide, and 2 to 3 mm thick, with the base of the leaf 5 to 8 mm wide. The upper sides of the leaves are flat to slightly concave, while the lower side is rounded, while the margins of the leaves are acute.

Reproductively morphology

The peduncle is glaucous, and tinged with a purple coloration on the lower third. It is erect, and reaches from 5 to 15 cm tall, 3 to 6 mm thick, with 5 to 15 bracts. The lower 3 cm of the peduncle is usually bare of these bracts. The bracts are ascending, shaped lanceolate with an acute tip, with the lowermost ones 8 to 10 mm long, and 5 to 7 mm wide. The inflorescence first branches 2 to 3 times, often in an obpyramidal shape. These branches in turn may be simple (not re-branching) or they may form bifurcate ascending branches. The terminal branches are circinate (coiled on themselves, like the frond of a fern), and in age are ascending. The terminal branches are 2 to 5 cm long, and have 2 to 10 flowers on them. The pedicels are ascending to erect in flower, and become definitively erect in fruit, with the lowermost 3 to 5 mm long, and 1 to 2 mm thick.

The calyx is 5 to 7 mm wide, and 4 to 5 mm high. The segments are shaped triangular, 3 to 5 mm long, 2 to 2.5 mm wide, with an acute tip. The corolla is shaped nearly conical in bud, colored yellow with a tinge of green on the midrib, and in anthesis is tubular, being slightly constricted at the mouth. The tube is 8 to 10 mm long, and 4 to 5 mm wide at the base, with the tips of the petals recurving to 90 degrees or more from vertical. The color of the petals is described as a lemon yellow, shaped oblong to lanceolate, with an acute tip, 10 to 14 mm long, and 2.5 to 4 mm wide in the middle, connate (fused to form a tube) 1 to 2 mm.

Flowering is from May to June. Chromosome number is n = 17, making this plant a diploid.

Taxonomy

Taxonomic history

This plant was first collected by botanist and ''Dudleya'' researcher Reid Moran in 1944. Moran and cytologist Charles H. Uhl later placed this plant as a population of ''Dudleya caespitosa'' in 1953. This was likely due to the fact that it had similar morphological characteristics, such as yellow petals, a glaucous rosette, and relatively thick, oblong-lanceolate leaves, which appear close to the population of ''D. caespitosa'' at Point Mugu. However, ''D. caespitosa'' is a polyploid species, and it is rarely diploid like ''Dudleya verityi''.

Peter H. Raven and Henry J. Thompson in their 1966 "Flora of the Santa Monica Mountains" placed this population as '' Dudleya farinosa'', which is closely related to ''D. caespitosa''. Their primary motive to place it as ''D. farinosa'' was probably because of the paler yellow flowers, caespitose habit and diploid chromosome number, which they believed fit better into the circumscription of ''D. farinosa'' instead of ''D. caespitosa''.

Despite these placements, this species has numerous unique characteristics that separate it from both ''D. caespitosa'' and ''D. farinosa''. The petal shape, along with the recurving petal tips and diploid chromosome count, are within the range of diagnostic distinctions used to separate species in this genus.

Botanist Kei M. Nakai later segregated the population by describing it as a species in its own right. He also noted the similarity of the flower morphology to nearby ''Dudleya cymosa'', particularly of the subspecies '' ovatifolia''. He hypothesized that ''D. verityi'' could have potentially emerged from a past hybridization event between ancestral ''D. cymosa'' and ''D. caespitosa'' populations, as this species has the floral characteristics of ''D. cymosa'' but the vegetative morphology of ''D. caespitosa''. Nakai also noted the existence of hybrids between ''Dudleya blochmaniae'' and this species.

Etymology

This species is named after David S. Verity, a horticulturist and entomologist who did work on ''Dudleya'' hybrids. David Verity hybridized many inter-subgeneric hybrids, even ones with varying levels of ploidy.

Ecology

This dudleya associates with mosses and lichen'', which may provide a moisture-capturing bed for seeds that fall from it. This dudleya hybridizes with other species, such as ''Dudleya blochmaniae''.

This species is only found on one edge of the Santa Monica Mountains, where it occurs in coastal sage scrub habitat. The dominant plants are California sagebrush (''Artemisia californica''), California buckwheat (''Eriogonum fasciculatum'') and purple sage (''Salvia leucophylla''). At least two occurrences are within the campus bounds of California State University, Channel Islands.

Conservation

It is a federally listed threatened species, with the main threat to its existence being destruction of its habitat for development, mining, and flood control. The Springs Fire in 2013 nearly wiped it out and the years-long drought that continued afterwards has made for a very tough recovery. Evidence of poaching was discovered in 2019.

References

External links

Jepson Manual TreatmentUSDA Plants ProfileFlora of North AmericaThe Nature ConservancyPhoto gallery

{{Taxonbar, from=Q5312068

verityi
Endemic flora of California
Natural history of the California chaparral and woodlands
Natural history of the Santa Monica Mountains
Natural history of Ventura County, California
Plants described in 1983