''Trichostema laxum'' is a species of flowering plant in the

mint family The Lamiaceae ( ) or Labiatae are a family of flowering plants commonly known as the mint, deadnettle, or sage family. Many of the plants are aromatic in all parts and include widely used culinary herbs like basil, mint, rosemary, sage, sav ...

, known by the common name turpentine weed from the foliage's scent.Jepson: ''Trichostema laxum''
/ref>

Distribution

The

annual plant An annual plant is a plant that completes its life cycle, from germination to the production of seeds, within one growing season, and then dies. Globally, 6% of all plant species and 15% of herbaceous plants (excluding trees and shrubs) are ...

is native to northern

California California () is a U.S. state, state in the Western United States that lies on the West Coast of the United States, Pacific Coast. It borders Oregon to the north, Nevada and Arizona to the east, and shares Mexico–United States border, an ...

and

Oregon Oregon ( , ) is a U.S. state, state in the Pacific Northwest region of the United States. It is a part of the Western U.S., with the Columbia River delineating much of Oregon's northern boundary with Washington (state), Washington, while t ...

, at elevations below . It is found primarily in the Inner Northern

California Coast Ranges The Coast Ranges of California span from Del Norte County, California, Del Norte or Humboldt County, California, south to Santa Barbara County, California, Santa Barbara County. The other three coastal California mountain ranges are the Trans ...

, including the subranges of the

Klamath Mountains The Klamath Mountains are a rugged and lightly populated mountain range in northwestern California and southwestern Oregon in the western United States. As a mountain system within both the greater Pacific Coast Ranges and the California Coast R ...

and the

Mayacamas Mountains The Mayacamas Mountains are located in northwestern California in the United States. The mountain range is part of the Northern Inner Coast Ranges, of the California Coast Ranges System. Geography The Mayacamas Mountains are located south of th ...

.Calflora: Distribution map in California
/ref> It grows in gravelly streambanks or sandy soil, of the mountains and foothills in

chaparral Chaparral ( ) is a shrubland plant plant community, community found primarily in California, southern Oregon, and northern Baja California. It is shaped by a Mediterranean climate (mild wet winters and hot dry summers) and infrequent, high-intens ...

, Foothill

oak woodland An oak woodland is a plant community with a tree canopy dominated by oaks (''Quercus spp.''). In terms of canopy closure, oak woodlands are intermediate between oak savanna, which is more open, and oak forest, which is more closed. Although the c ...

, and

Yellow pine forest Ponderosa pine forest is a plant association and plant community dominated by ponderosa pine and found in western North America. It is found from the British Columbia to Durango, Mexico. In the south and east, ponderosa pine forest is the climax ...

habitats. The species has an affinity for

serpentine soil Serpentine soil is an uncommon soil type produced by weathered ultramafic rock such as peridotite and its metamorphic derivatives such as serpentinite. More precisely, serpentine soil contains minerals of the serpentine subgroup, especially an ...

Description

''Trichostema laxum'' is an annual herb approaching in maximum height. Its aromatic foliage, with a strong

turpentine Turpentine (which is also called spirit of turpentine, oil of turpentine, terebenthine, terebenthene, terebinthine and, colloquially, turps) is a fluid obtainable by the distillation of resin harvested from living trees, mainly pines. Principall ...

odor, is coated in glandular and nonglandular hairs. The lanceolate to narrowly ovate leaves are up to 7 centimeters long. The

inflorescence In botany, an inflorescence is a group or cluster of flowers arranged on a plant's Plant stem, stem that is composed of a main branch or a system of branches. An inflorescence is categorized on the basis of the arrangement of flowers on a mai ...

is a series of clusters of flowers located at each leaf pair. Each flower has a hairy calyx of green or reddish

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 Etymology The term ''sepalum'' ...

s and a tubular, lipped purple corolla. The four

stamen The stamen (: stamina or stamens) is a part consisting of the male reproductive organs of a flower. Collectively, the stamens form the androecium., p. 10 Morphology and terminology A stamen typically consists of a stalk called the filament ...

s are long and curved, measuring up to 1.6 centimeters in length. Its bloom period is from June to October.

References

External links

Calflora: ''Trichostema laxum'' (Turpentine weed)Jepson Manual eFlora (TJM2) treatment of ''Trichostema laxum''USDA Plants Profile for ''Trichostema laxum'' (turpentine weed)UC Photos gallery: ''Trichostema laxum''
laxum Flora of California Flora of Oregon Natural history of the California chaparral and woodlands Natural history of the California Coast Ranges Flora of the Klamath Mountains Mayacamas Mountains Flora without expected TNC conservation status {{Lamiaceae-stub