1	"Well developed ray flowers 0; ray of pistillate flowers 0 or pistillate flowers 0"	2
1	"Well developed ray flowers generally present, ray evident"	3
2	"Disk flowers generally 4; corolla 3-lobed"	"Pentachaeta alsinoides"
2	"Disk flowers 6--34; corolla 5-lobed"	"Pentachaeta exilis subsp. exilis"
3	"Ray flowers white, ray sometimes +- red abaxially; pappus bristles present or 0"	4
3	"Ray flowers generally yellow or proximally yellow, distally white, sometimes +- brown-orange; pappus bristles present"	5
4	"Ray flowers 7--16; peduncle glabrous to short-hairy"	"Pentachaeta bellidiflora"
4	"Ray flowers (0)1--3; peduncle soft-shaggy-hairy"	"Pentachaeta exilis subsp. aeolica"
5	"Ray flowers 7--12, disk flowers 10--23; largest leaves < 2.5 cm"	"Pentachaeta fragilis"
5	"Ray flowers 14--52, disk flowers 30--91; largest leaves 2.5--5.5 cm"	6
6	"Phyllaries lanceolate, soft-shaggy-hairy; pappus bristles 8--12"	"Pentachaeta lyonii"
6	"Phyllaries narrowly to widely-elliptic, glabrous or sparsely short-hairy; pappus bristles 5--8"	7
7	"Ray proximally yellow, distally white"	"Pentachaeta aurea subsp. allenii"
7	"Ray yellow to orange"	"Pentachaeta aurea subsp. aurea"