Southwest Colorado Wildflowers, Lomatium

Accurate identification of the several dozen species of Lomatium is, according to Intermountain Flora, "notoriously difficult.... Some species are highly variable...." Both fruits and flowers are often necessary for identification. Intermountain Flora further observes that "the distinction between Cymopterus and Lomatium is subject to failure. Ordinarily one or more of the dorsal ribs [of the seeds have wings in] Cymopterus, but not in Lomatium. Cymopterus newberryi completely bridges the difference. In this species the dorsal wings vary from nearly or fully as large as the lateral ones to poorly developed or even obsolete".

"Loma" is Greek for "border" and refers to the small wings of the fruit. The genus was named by Constantine Rafinesque (1783-1840) in 1819.

See more Lomatiums and the similar genera Cymopterus and Podistera and Oreoxis.

Lomatium dissectum (Giant Lomatium)
Apiaceae (Parsley Family)

Semi-desert, foothills. Shrublands, woodlands, openings. Spring.
Prater Ridge Trail, Mesa Verde National Park, May 2, 2006.

Lomatium disectum has large, handsome, highly dissected leaves surmounted by a flower stalk up to 40 inches tall. Flowers start in a tight circle, as shown in the thumbnail photo, and spread in a golden wheel formation over six inches in diameter. The plant is often found on open rocky slopes and dry meadows.

Thomas Nuttall named this species Leptotaenia dissecta from a specimen he collected in Oregon in the mid-1830s. Mathias and Constance renamed it Lomatium disectum in 1942.

Lomatium dissectum (Giant Lomatium)
Apiaceae (Parsley Family)

Semi-desert, foothills. Shrublands, woodlands, openings. Spring.
Prater Ridge Trail, Mesa Verde National Park, May 2, 2006.

Lomatium dissectum (Giant Lomatium)
Apiaceae (Parsley Family)

Semi-desert, foothills. Shrublands, woodlands, openings. Spring.
Prater Ridge Trail, Mesa Verde National Park, May 2, 2006.

Leaves are very similar to those of Ligusticum porteri but are generally shinier and not mottled as those of Ligusticum commonly are. Lomatium disectum has yellow flowers in the spring; Ligusticum porteri has white flowers in the summer. The ranges overlap in the lower mesas but only L. porteri is found in the higher mountains.

Lomatium grayi (Biscuitroot)
Apiaceae (Parsley Family)

Semi-desert, foothills. Shrublands, woodlands, openings. Spring.
Dolores River Overlook Trail, April 25, 2007.

This is a wide-spread and abundant Lomatium in the Four Corners area, but it is, according to Intermountain Flora, missing from Utah Canyon Country. It is quite abundant in some areas of Mesa Verde National Park. Leaves are subdivided into numerous, fine segments that turn in different planes, giving the plant a very thick, fern-like appearance. Flower stalks often lean, rather than growing vertically.

The first specimen of this plant was collected by Sereno Watson on Antelope Island in the Great Salt Lake in Utah around 1868 and was named Peucedanum milleflium by Watson. It was renamed several times until in 1900 John Merle Coulter and Joseph Rose gave the present name. Asa Gray was a student of the great John Torrey, and Watson was Gray's student. The three dominated 19th century American botany. (More biographical information.)

Lomatium grayi ( Biscuitroot)
Apiaceae (Parsley Family)

Semi-desert, foothills. Shrublands, woodlands, openings. Spring.
Top photo: Prater Ridge Trail, Mesa Verde National Park, May 2, 2006.
Bottom two photos: Dolores River Overlook Trail, April 25, 2007.