Note that the keys to the species in Budd's Flora and Flora of Alberta require:

stems solitary; NOT [stems several to many]

In fact, occasionally several stems arise from the base of the plant, as they do in the specimens pictured here.

Note that the keys to the species in Budd's Flora and Flora of Alberta require:

basal rosettes absent when flowering; NOT [basal rosettes persistent]

In fact, sometimes some basal leaves will persist, although these are often brown or turning brown.

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

involucre of one series of equal bracts; NOT [involucre usually of unequal bracts]

This is not true.  There is an outer series of unequal bracts, the longest of which are about 1/3 as long as an inner series of equal, elongate bracts.  The corresponding entry in Flora of Alberta is simply illogical:

involucre of 2 or more series; NOT [involucre uniseriate or biseriate]

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

 

Tectorum:  Answers to key questions in Budd's Flora (BF) and Flora of Alberta (FOA) leading to this species.   plants annual; NOT [plants perennial, with a taproot] (FOA) (BF) stem with many stalkless leaves; NOT [stem with few and smaller stem leaves] ] (BF) cauline leaves auriculate; NOT [cauline leaves, if present, not auriculate] (FOA) achenes more than 2.5 mm long (FOA)

Crepis: Answers to key questions in Budd's Flora and Flora of Alberta leading to this genus.  Not all of the answers apply to all members of Crepis found in the Canadian prairies, but they all do apply to this species. annuals or taprooted perennials; NOT [perennials with fibrous roots] (FOA) juice milky; NOT watery (FOA, BF) NOT [stem diffusely branched; leaves few, cauline, mostly linear or reduced to scales] (FOA) leaves broader and leaf-like; NOT [leaves narrowly linear or scale-like] (BF) plants with at least some cauline leaves, though they may be reduced to bracts; NOT [plants scapose, leaves all basal] (FOA) plants with normal stem leaves; NOT [plants with leaves all basal or with a few reduced leaves on the stem] (BF) stems leafy throughout or at least to mid-way up the stem; NOT [stems leafy at the base only, leaves mostly basal] (BF) lower stem and leaves generally glabrous, sometimes puberulent, tomentose or hispid; NOT [lower stem and leaves generally long-hairy] (FOA) heads few to many, rarely solitary; NOT [heads solitary] (FOA) flowers all ligulate  (FOA, BF) flowers all perfect (FOA) flowers yellow (BF, FOA) stamens united to form a tube around the pistil (BF) achenes NOT flattened; NOT [achenes flattened, at least twice as wide as thick] (FOA, BF) pappus well developed, at least in part of capillary bristles; NOT [pappus of minutes scales or none] (FOA, BF) pappus simple, consisting of bristles only; NOT [pappus double, the outer ring consisting of 5 small scale-like appendages, the inner ring bristles] (BF),  NOT [pappus scale-like at the base, with plumose terminal bristles] (FOA) pappus bristles simple; NOT [pappus bristles plumose (branched)] (BF, FOA) pappus white; NOT [brownish or tawny] (BF)