In California, Lomatium foeniculaceum is represented by 3 of the five races treated by Theobold (Brittonia 18:1-18. 1966) and Holmgren (Intermountain Flora Vol. 3A. 1997). Records attribute all of the Modoc Plateau occurrences as Lomatium foeniculaceum var. macdougalii, CNPS List 2.2, a rare plant.
Holmgren and TJM2 keys respectively distinguish var. fimbriatum on the basis of “petals ciliolate margined (unique in the species)” and “petal margin minutely ciliate”.
Plants of the population of Lomatium foeniculaceum on the southerly outskirts of Alturas were in flower this year on May 16th. Plants in this occurrence have petals that are NOT glabrous on the surface nor on the petal margin, making them similar to the circumscription of var. fimbriatum. The EO#10 plants do not have the very regular, minutely ciliate petal margins with glabrous petal faces illustrated in Intermountain Flora Vol. 3A p. 407. Rather, they are have irregular, dense trichomes over both the petal surface and irregularly along the petal margin.
Many of the Modoc County locations of Lomatium foeniculaceum lack a voucher specimen, making determination of the petal glabrous/pubescent feature uncertain. Lomatium foeniculaceum var. fimbriatum was described from a White Mountain, Inyo County type attributed to deposition at LA. The holotype was not cited as seen by Holmgren (Intermountain Flora Vol. 3A. 1997) nor are any isotypes in any of the major herbaria databases (NY, MO, US, UC). In the CNPS Inventory the statement is made "Lassen County plants may be undescribed". Indeed, perhaps there is a 6th infrataxon of Lomatium foeniculaceum, one in which the petals are pubescent but regularly fimbriate as in var. fimbriatum.
The relatively poor photo shows a magnified image of the flowers and their abundant petal trichomes (red arrows show examples)