1	"Petals yellow to yellow-orange, drying +- red or not"	2
1	"Petals white to pink, red, purple-rose, or purple"	7
2	"Annual; fruit < 5 mm"	"Oxalis micrantha"
2	"Perennial herb; fruit >= 6 mm or 0"	3
3	"Leaves in loose, +- basal rosette; bulbs present"	"Oxalis pes-caprae"
3	"Leaves cauline; bulbs 0"	4
4	"Petals 12--20 mm; NCo"	"Oxalis suksdorfii"
4	"Petals 5--12 mm; NCo, elsewhere"	5
5	"Petals generally < 8 mm; stem rooting at nodes; taproot fibrous"	"Oxalis corniculata"
5	"Petals generally 8--12 mm; stem not rooting at nodes; taproot +- woody"	6
6	"Hairs generally sparse, appressed or arched upward; pedicels > 2 &times; fruit"	"Oxalis californica"
6	"Hairs dense, generally spreading; pedicels < 2 &times; fruit"	"Oxalis pilosa"
7	"Bulbs 0"	8
7	"Bulbs present"	10
8	"Rhizome woody, not creeping; disturbed places"	"Oxalis articulata subsp. rubra"
8	"Rhizome fleshy, creeping; +- undisturbed forests"	9
9	"Flowers 1"	"Oxalis oregana"
9	"Flowers 3--9 in umbel-like cyme"	"Oxalis trilliifolia"
10	"Stem elongate"	"Oxalis incarnata"
10	"Stem +- 0"	11
11	"Flowers in umbel-like cyme"	"Oxalis bowiei"
11	"Flowers 1"	"Oxalis purpurea"