Note that the key to the genera in Budd's Flora requires:

leaves much divided, with leaflets or segments numerous; NOT [leaves simple or divided into few well developed leaflets]

This is not true.

Note that the key to the genera in Flora of Alberta requires:

leaves once pinnate; NOT [leaves 2 or more times pinnate or ternate]

In fact, the leaves of this species can be once or twice pinnate.

The rest of the answers to the key questions are listed below.

 

Perideridia: Answers to key questions in Budd's Flora and Flora of Alberta leading to this genus. NOT [plants with a bluish tinge; flowers in dense globose heads; bracts spiny] plants with stem leaves; NOT [plants scapose] lower stem leaves alternate, stem leaves sometimes opposite in the inflorescence; NOT [lower stem leaves opposite] foliage NOT spiny lowest leaves (and the upper) compound; NOT [lowest leaves simple] foliage NOT digitately compound NOT [leave usually trifoliate, leaflets palmate, 10-30 cm wide] leaves pinnate, trifoliate, or simple; NOT [leaves palmate with 5-7 large leaflets] leaf segments few, usually 5, long and linear; NOT [leaf segments more than 5] leaflets mostly 1–2 mm wide; NOT [leaflets more than 2 mm wide] leaflets entire; NOT serrate plants NOT with axillary bulblets largely replacing flowers inflorescence NOT bluish umbel compound; NOT simple umbel many-flowered; NOT few-flowered involucral bracts small; NOT large involucral bracts slightly or not dissected; NOT [involucral bracts pinnately dissected] fruit about 2 mm long; NOT [fruit generally more than 2 mm long] fruit generally 3 times as long as broad or less; NOT [fruit several times longer than broad] fruit oblong to elliptical; NOT [fruit linear to clavate] fruit NOT with hooked spines

 

Umbelliferae: Answers to key questions in Budd's Flora leading to this family. herbs; NOT [shrubs or trees] plants terrestrial or semi-aquatic; NOT [plants aquatic, leaves submerged or floating] plants NOT with colored milky juice stems hollow plants with more than one normal leaf some or all leaves alternate; NOT [leaves opposite, whorled, or basal] leaves without stipules, or having glands; NOT [leaves with stipules] flowers in umbels flowers with two floral rings, and with each petal distinct from the others parts of flowers mostly in fives; NOT [parts of flowers in twos or fours] calyx regular stamens 10 or fewer; NOT [stamens usually more than 10] styles 2; NOT 5 ovary inferior; NOT superior