Thomas J. Howell

Trillium chloropetalum, also known as giant trillium, giant wakerobin, or common trillium, is a species of flowering plant in the family Melanthiaceae. It is endemic to the western U.S. state of California, being especially frequent in and around the San Francisco Bay Area.

Iris chrysophylla, the yellowleaf iris, is a wildflower which ranges from midwestern and southern Oregon west of the Cascades and south to the crest of the Siskiyou Mountains in northern California. The yellowleaf iris grows up to 5,500 feet (1,700 m) elevation, most commonly in open, coniferous forests.

Thermopsis gracilis is a species of flowering plant in the legume family known by the common name slender goldenbanner. It is native to the western United States from Washington state to northern California. It grows in open mountain forests and other habitats.

Cardamine occidentalis is a species of Cardamine known by the common name big western bittercress. It is native to western North America from Alaska to northwestern California, where it grows in moist mountain habitats.

Campanula piperi (Olympic bellflower, Olympic harebell, Piper's bellflower) is a species of flowering plant in the bellflower family, Campanulaceae. It is native to the Olympic Mountains on the Olympic Peninsula in the U.S. state of Washington. It has also been noted on Vancouver Island, British Columbia.

Arctostaphylos hispidula is a species of manzanita known by the common names Gasquet manzanita and Howell's manzanita. It is native to the coastal mountain ranges of southern Oregon and northern California, where it is an uncommon member of the serpentine soils flora and other mountain plant communities. This is a spreading or erect shrub reaching a maximum height between one and two meters. The twigs and foliage are bristly and glandular, the dark green leaves oval to broadly lance-shaped and up to 3 centimeters long. The shrub blooms in crowded inflorescences of urn-shaped flowers and

Rorippa columbiae is a species of flowering plant in the family Brassicaceae known by the common names Columbian yellowcress and Columbia yellow cress.

Ribes acerifolium is a North American species of currant known by the common names mapleleaf currant and maple-leaved currant. It is native to the Canadian Province of British Columbia as well as to the northwestern United States (Washington, Idaho, Oregon). Ribes acerifolium is a trailing shrub up to 100 cm (40 inches) tall, with red or pink flowers and black berries.

Penstemon rupicola is a species of penstemon known by the common names cliff beardtongue or rock penstemon. It is native to the west coast of the United States from Washington to the Klamath Mountains of far northern California, where it grows in rocky mountainous habitat. It is a clumpy, mat-forming subshrub growing no more than 14 centimeters high. The thick, waxy, oppositely arranged leaves are round or oval and up to 2 centimeters long. The showy wide-mouthed tubular flowers emerging from the mat may be nearly 4 centimeters in length and are shades of light purple to bright pink. It has

Monardella purpurea is a species of flowering plant in the mint family known by the common names Siskiyou monardella and serpentine monardella. It is native to the mountains of northern California and southern Oregon, including the Klamath Mountains. It grows in rocky slopes, chaparral, woodlands, montane forests and serpentine soils.

Geranium oreganum is a species of geranium known by the common name Oregon cranesbill, or Oregon geranium. It is native to western North America from California to Alberta, where it grows in mountain forests and meadows. This is a perennial herb growing generally erect to heights of 40 to 80 centimeters. The slender stems have a foliage of large palmate leaves up to 15 centimeters wide and divided into several segments, each of which is subdivided into rounded or pointed lobes. The flower has pointed sepals beneath rounded lavender to purple petals. The fruit has a small body with a pointed

Calochortus superbus is a North American species of flowering plants in the lily family known by the common name superb mariposa lily. It is endemic to California, a common member of the flora in several types of habitat across much of the state. It is most abundant in the Coast Ranges and in the Foothills of the Sierra Nevada.

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Pleuropogon hooverianus is a rare species of grass known by the common name North Coast semaphoregrass. It is endemic to northern California, where it is known from Mendocino, Marin, and Sonoma Counties. It grows in moist marshy areas and shady redwood forests. It is an erect perennial grass growing to a maximum height between one and 1.6 meters. The inflorescence bears widely spaced narrowly cylindrical spikelets which hang sideways off the stem, resembling semaphore signals. Each spikelet may be up to 4.5 centimeters long and may contain up to 16 flowers.

Limnanthes floccosa, or woolly meadowfoam, is a species of meadowfoam found in Northern California and Southern Oregon, in the United States. Most of the subspecies have highly restricted distributions and are listed as critical or endangered. Perhaps the most familiar subspecies of woolly meadowfoam is californica, not because it is the one most often seen (it is very inconspicuous), but because this taxon has been the focus of a significant conflict. The subspecies is found only among a dozen or so populations in Butte County, California, and is legally protected as endangered. Conflict has

Erigeron aliceae is a species of flowering plant in the family Asteraceae known by the common name Alice Eastwood's fleabane, or simply Alice's fleabane. It was named for American botanist Alice Eastwood, 1859 - 1953. Erigeron aliceae is a perennial native to the meadows and woodlands of the Pacific Northwest. It is found in western Washington, western Oregon, and the northwestern corner of California (Del Norte, Humboldt, Trinity, and Siskiyou Counties). There is a report of an isolated population in the Sierra Nevada east of Yuba City, but this might be an escape from cultivation. Erigeron

Phoradendron libocedri is a species of flowering plant in the sandalwood family known by the common name incense-cedar mistletoe. It is native to western North America from Oregon to Baja California, where it grows in forests on its host tree, the California incense-cedar (Calocedrus decurrens). This mistletoe is a shrub producing greenish erect, hanging, or drooping branches from a woody base where it grows attached to the tree, parasitizing it for water and nutrients. As a hemiparasite it contains some chlorophyll and can photosynthesize some energy for itself as well. The smooth, noded

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Lupinus saxosus is a species of lupine known by the common name rock lupine. It is native to eastern Washington, eastern Oregon, and the northeast corner of California,where it grows in sagebrush and other habitat. It may also be native to Idaho and Nevada.

Hieracium longiberbe, known by the common name longbeard hawkweed, is a rare North American plant species in the tribe Cichorieae within the family Asteraceae It has been found only in the Columbia River Gorge along the border between the states of Washington and Oregon in the northwestern United States. Hieracium longiberbe is an herb up to 50 cm (20 in) tall, with leaves mostly on the stem rather than in a rosette at the bottom. Leaves, stems, and the bracts surrounding the flower heads are covered with long and conspicuous hairs up to 8 mm (0.31 in) long. Leaves are up to 100 mm (3.9 in)

Eriogonum ternatum is a species of wild buckwheat known by the common name ternate buckwheat. It is native to mountain ranges of northern California and southern Oregon, where it grows in the serpentine soil of the forests. This is a perennial herb forming mats up to half a meter wide with rosetted clusters of oval to rounded woolly leaves each about a centimeter long. The inflorescence arises on a flowering stem and bears an umbel of bright yellow flowers.

Arnica cernua is a species of arnica known by the common name serpentine arnica. It is native to the Klamath Mountains of northern California and southern Oregon, where it is a member of the serpentine soils flora. This is a perennial herb growing one or more green to purplish stems up to about 30 centimeters tall. There are 3 or 4 pairs of leaves on long petioles. The blade is oval to spade-shaped and may be several centimeters long. The inflorescence contains one or more hairy, glandular, daisylike flower heads, each with a center of yellowish disc florets and a fringe of yellow ray florets

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Lithophragma campanulatum is a species of flowering plant in the saxifrage family known by the common name Siskiyou Mountain woodland star. It is native to southern Oregon and northern California, where it grows in the forests and woods of the mountains. It is a rhizomatous perennial herb growing erect or leaning with a tall naked flowering stem. The leaves are mostly located on the lower part of the stem, each divided into rounded lobes, sometimes narrowed into teeth. The stem bears 2 to 11 flowers, each in a cuplike calyx of red or green sepals. The five petals are white, under one

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