Chrysopsis (Heterotheca): Answers to key questions in Budd's Flora (BF) and Flora of Alberta (FOA) leading to this genus.  Note that the keys in Budd's Flora and Flora of Alberta have somewhat conflicting requirements about the number of heads.  Budd's Flora is trying to distinguish Chrysopsis and Haplopappus from Solidago with its statement. plants more than 15 cm tall juice watery; NOT milky stems leafy almost to inflorescence; NOT [leaves mostly basal, with stem leaves reduced] leaves alternate or basal; NOT opposite heads several; NOT solitary (FOA) heads usually solitary at ends of branches; NOT [heads small and numerous, in terminal or axillary clusters] (BF) involucral bracts in 2 or more series, well imbricated; NOT [involucral bracts usually one series, not or scarcely imbricated] receptacle naked flower heads with florets both tubular and ray ligulate florets pistillate or neuter; NOT [ligulate flowers perfect] ray florets yellow; NOT [ray florets usually blue, purple or white to pink] stamens united to form a tube around the pistil pappus composed of hairs; NOT [pappus, when present, composed of scales or bristles] pappus double, bristles of the outer series inconspicuous, distinctly shorter than the inner; NOT [pappus single, bristles sometimes unequal but not distinctly divided into an inner and outer series of two lengths]