Hyssopifolius: Answers to key questions in Budd's Flora and Flora of Alberta leading to this species. 

	plants not producing leafy stolons
	plants usually more than 20 cm high; NOT [plants usually less than 20 cm high]
	basal rosette often not present; NOT [basal rosette generally present]
	NOT [basal leaves lobed or toothed, occasionally entire; cauline leaves auriculate-clasping]
	stem leaves numerous; NOT [stem leaves 0-3, leaves mainly basal]
	stem leaves at middle of stem longer than those above and below; NOT [stem leaves gradually reduced upward] (BF)
	leaves not much reduced in size upwards; NOT [leaves often markedly reduced upwards] (FOA)
	leaves 1-3 mm wide; NOT [leaves more than 3 mm wide]
	leaves more or less entire, not dissected, trifid or lobed at the apex; NOT [leaves dissected, or at least some trifid or lobed at the apex]
	leaves linear to oblanceolate; NOT [leaves lanceolate to oblanceolate or spatulate]
	leaves essentially glabrous; NOT [leaves coarsely pubescent, with appressed or spreading white hairs]
	heads usually more than one; NOT [heads solitary]
	peduncles straight; NOT [peduncles arcuate]
	involucre at least 6 mm high; NOT [involucre 4-5 mm high]
	involucre glabrous; NOT [involucre pubescent, generally glandular]
	involucres NOT woolly-villose
	involucre NOT glandular
	NOT [involucre deep purple; densely villous, the hairs with purple septa]
	heads with well-developed ray florets; NOT [heads discoid or with short inconspicuous ray florets] (BF)
	rays absent, inconspicuous or short, not more than 5 mm long; NOT [rays present, longer than 5 mm] (FOA)
	rays not yellow

Erigeron: Answers to key questions in Budd's Flora and Flora of Alberta leading to this genus. 

	juice watery; NOT [juice milky]
	leaves appearing before the flowers; NOT [leaves appearing after the flowers]
	plants usually with leafy stems; NOT [plants low, stemless, tufted]
	basal leaves NOT cordate or sagittate
	NOT [basal leaves mostly 1-6 cm long, linear to oblanceolate or spatulate, forming a dense rosette; plants with a well-developed taproot; and either densely caespitose, seldom more than 5 cm tall, the heads sessile among the leaves, or with stout, simple stems, 5-15 (25) cm tall, heads solitary, involucres 2-4 cm wide, bracts ciliate to pectinate or fimbriate, rays blue and achenes densely pubescent, obovate to triangular]
	leaves alternate or basal; NOT [leaves opposite]
	leaves not extending beyond flowers; NOT [leaves usually extending beyond the flowers]
	involucral bracts subequal or more or less imbricate, often green in part, but neither definitely leafy nor with chartaceous base and herbaceous green tip; NOT [involucral bracts either subequal and the outer leafy or more commonly evidently imbricate, with chartaceous base and evident green tip, sometimes chartaceous throughout] (FOA)
	bracts in 1 or 2 series; NOT [bracts in several series] (BF)
	flower heads with both tubular florets and ray florets (radiate heads)
	ligulate florets pistillate or neuter; NOT [ligulate flowers perfect]
	ray florets conspicuous
	ray florets 50 or more; NOT [ray florets 10-50] (BF)
	rays white, to pink, purple or blue; NOT [rays yellow or orange]
	stamens united to form a tube around the pistil
	style-branches 0.5 mm long or less, or obsolete; NOT [styles-branches ordinarily more than 0.5 mm long]
	style-branches lanceolate or broader; NOT [style-branches lanceolate or narrower]
	style-branches acute to obtuse; NOT [style-branches acute or acuminate]
	pappus composed of numerous hairs; NOT [pappus absent or composed of a few hairs] (BF)
	pappus of capillary bristles, at least in part; NOT [pappus of 1 or 2 short awns, a mere crown or none] (FOA)