Perideridia kelloggii (A. Gray) Mathias

Perideridia kelloggii (A. Gray) Mathias, Brittonia 2: 244. 1936
Carum Kelloggii A. Gray, Proc. Am. Acad. 7: 344. 1868. Ataenia Kelloggii Greene, Pittonia 1: 274. 1889.
Stout, from a fascicle of fibrous or slightly thickened roots, 7-15 dm. high; leaves deltoid in general outline, excluding the petioles 15-30 cm. long, 1-2-ternate-pinnate, the ultimate divisions linear to lanceolate, entire, 3-12 cm. long, 1-6 mm. broad; petioles 4-7 cm. long, often sheathing throughout; peduncles slender, 5-18 cm. long; involucre of several linear to linearlanceolate, more or less scarious, reflexed bracts, 5-15 mm. long; involucel of several linear to lanceolate, more or less scarious, eventually reflexed bractlets, 2-6 mm. long, often longer than the flowers but shorter than the fruit; rays 10-20, 15-65 mm. long; pedicels 2-6 mm. long; styles divergent, about 0.5 mm. long; stylopodium conic; fruit oblong, 4-5 mm. long, 2-3 mm. broad; oil-tubes solitary in the intervals, 2 on the commissure; seed sulcate under the tubes, the face plane to slightly concave with a commissural ridge.
Type locality: San Jose, Santa Clara County, California, Brewer 832.
Distribution: Sierra Nevada and Coast Ranges of northern and central California (Heller 7535. Jones 29,049).

Perideridia kelloggii is a species of flowering plant in the family Apiaceae known by the common name Kellogg's yampah. It is endemic to California, where it is known from the north and central coasts, the San Francisco Bay Area, and the Sierra Nevada foothills. It grows in grassland habitat, sometimes on serpentine soils. It is a perennial herb which may reach 1.5 meters in maximum height, its slender, erect stem growing from a cluster of long, narrow, fibrous roots each up to 15 centimeters long. Leaves near the base of the plant have blades up to 45 centimeters wide which are divided into many leaflets subdivided into narrow, elongated lobes. The inflorescence is a compound umbel of many spherical clusters of small white flowers. These yield ribbed, oblong-shaped fruits each about half a centimeter long.

Perideridia kelloggii là một loài thực vật có hoa trong họ Hoa tán. Loài này được (A. Gray) Mathias mô tả khoa học đầu tiên năm 1936.