Diario de jhorthos

https://botanicgardens.uw.edu/wp-content/uploads/sites/7/2016/11/Darrach-2017_Lomatium-%E2%80%93-WA-Botanical-Symposium.pdf

By molecular studies, Lomatium and Cymopteris (and a few Tauschia and others) are extensively interdigitated, which appears not to have fully penetrated to formal naming. George et al 2014 Phylogenetic Analysis Reveals Multiple Cases of Morphological Parallelism and Taxonomic Polyphyly in Lomatium .

Crush some leaves and smell them! Hmm they all seem to smell of cedar and turpentine roughly.

Cymopterus terebinthinus - hmm except when fruiting looks a lot like a medium to big yellow Lomatium.

L. ambiguum - https://www.inaturalist.org/observations/156334613
L. brandegeei - montane, medium to largish, deeply divided leaves, medium to narrow width leaflets with highly visible veination, yellow flowers, common in serpentine Wenatchees and more widely in Cascades despite being listed as vulnerable. https://www.inaturalist.org/observations/127119593 and https://www.inaturalist.org/observations/167719744
L. canbyi - small early flowering white with fairly distinctive leaflets, https://www.inaturalist.org/observations/154148039
L. columbianum - large and bushy rose flowers, unmistakable when in flower and even after, https://www.inaturalist.org/observations/149290580 and https://www.inaturalist.org/observations/149326711
L. cuspidatum - serpentine, distinctive leaves, https://www.inaturalist.org/journal/jhorthos/68301-lomatium-cuspidatum-non-technical
L. dissectum (Fernleaf) - large bushy, dark red or yellow flowers, wider leaflets than L. multifidum, https://www.inaturalist.org/observations/153198930
L. farinosum - see L. triternatum
L. geyeri - small, white flowers with fairly narrow leaflets, https://www.inaturalist.org/observations/150448123
L. gormanii - tiny white flowered, very early flowering, https://www.inaturalist.org/observations/149332671
L. hallii - small to medium, yellow flowers, found in Oregon including Siskiyous, https://www.inaturalist.org/observations/152053418
L. howellii - uncommon, distinctive wide toothed leaflets, mostly on Klamath serpentine, https://www.inaturalist.org/observations/122515620
L. klickitatense - large puffy finely dissected, leaflets longer than L. papilioniferm, yellow flowers, https://www.inaturalist.org/observations/149327085 and https://www.inaturalist.org/observations/149328613
L. laevigatum - very narrow range mostly Columbia Transect, large yellow with long leaflets, involucre nearly absent, https://www.inaturalist.org/observations/154127684
L. macrocarpum - medium sized, ground hugging, green-white flowers, hairy floral stalks and bracts, cusped leaflet tips, https://www.inaturalist.org/observations/153200598
L. martindalei - montane, small, usually prostrate, wide leaflets, yellow flowers, https://www.inaturalist.org/observations/128448751
L. multifidum (Carrotleaf) large bushy highly dissected leaf, dark red or yellow flowers, very similar to L. dissectum but narrower leaf segments, https://www.inaturalist.org/observations/155156511
L. nudicaule - sometimes montane, medium to large, broad-leaved, yellow flowers, large swollen base where umbels branch, https://www.inaturalist.org/observations/117401560
L. papilioniferum - large showy yellow flowered, distinctive highly dissected leaves with short terminal leaflets, one of few on rock cliffs, extremely common in Columbia transect, https://www.inaturalist.org/observations/154112604
L. quintuplex - small yellow flowered with highly dissected leaves and cusped nearly cylindrical leaflets, in marginal rocky sites. (convergent on or related to cuspidatum?) - https://www.inaturalist.org/observations/158648966
L. roneurum - distinctive leaves, narrow range on Chumstick and adjacent gneiss rocks, https://www.inaturalist.org/observations/155090697
L. triternatum - small to medium, long narrow leaflets, dense short hairs on rachis, sometimes disorganized looking leaves, yellow flowers, https://www.inaturalist.org/observations/154127265
L. tuberosum - rare adorable plant, very distinctive foliage, https://www.inaturalist.org/observations/154108537, fruits at https://www.inaturalist.org/observations/115128062
L. utriculatum - small lowland coastal, yellow flowers, https://www.inaturalist.org/observations/152889731

B. hookeri - common, foxtail leaves, https://www.inaturalist.org/observations/115263062
B. sagittata - large, very common, https://www.inaturalist.org/observations/152379363

Most common and widespread are P. conjugens and P. pauciflora.

One distinguishing trait is the way the flower tube join near their top:
smoothly connected, appearing almost merged into a cylinder is P. pauciflora
clearly separated with deep clefts between them is P. conjugens, which is also less common and never on the west side (which sounds opposite, presumably conjugens doesn't refer to the tube joins)