1	"Annual to per"	2
1	"Subshrub to tree"	22
2	"Plant 1--2 m; leaves 2--3-pinnately compound; flowers unisexual; fruit follicles"	"Aruncus {Aruncus dioicus var. acuminatus}"
2	"Plant generally < 1 m; leaves simple to 1-ternately or 1-palmately or 1-pinnately compound, including 2-ternately dissected; flowers generally bisexual; fruit achenes or follicles"	3
3	"Petals 0, sepals generally 4; fruits 1(3) per flower, inside +- urn-shaped hypanthium"	4
3	"Petals, sepals generally 5; fruits 1--many per flower, on or outside shallow to +- obconic hypanthium"	8
4	"Leaf palmately lobed; inflorescence few-flowered cluster, axillary, +- hidden by sheathing stipules; hypanthium not hardened in fruit; annual"	"Aphanes {Aphanes occidentalis}"
4	"Leaf pinnately compound; inflorescence head or spike, axillary or terminal, not hidden; hypanthium +- hardened in fruit; generally per"	5
5	"Hypanthium +- prickly, not angled in fruit; stamens 2 or 4"	Acaena
5	"Hypanthium not prickly, 4-angled in fruit; stamens 0--many"	6
6	"Leaflets lobed > 2/3 to midvein; annual, biennial; basal leaves withered at flower"	"Poteridium {Poteridium annuum}"
6	"Leaflets toothed < 1/3 to midvein; perennial herb; basal leaves not withered at flower"	7
7	"Largest leaflet blade generally 5--20 mm, on stalk generally 1--4 mm, teeth generally < 15; stamens many, filaments thread-like; open, especially disturbed areas; CA-FP (except SNH)"	"Poterium {Poterium sanguisorba}"
7	"Largest leaflet blade 25--50 mm, on stalk 3--25 mm, teeth generally > 15; stamens 2--4, filaments not thread-like; bogs, streams; c NCo, nw KR, n NCoRO"	"Sanguisorba {Sanguisorba officinalis}"
8	"Leaves +- 2-ternately dissected, segments linear; fruit follicles"	"Luetkea {Luetkea pectinata}"
8	"Leaves simple to compound, ternately compound or not but not ternately dissected, segments linear or not or 0; fruit achenes, sometimes fleshy-coated (<i>Rubus</i>) or on fleshy receptacle (<i>Duchesnea</i>, <i>Fragaria</i>)"	9
9	"Hypanthium obconic to cup-shaped, rim with hooked bristles; inflorescence +- raceme"	Agrimonia
9	"Hypanthium generally shallower than obconic to cup-shaped, rim without hooked bristles; inflorescence generally cyme or flowers 1"	10
10	"Hypanthium bractlets 0; achenes fleshy-coated, finely hairy"	Rubus
10	"Hypanthium bractlets generally present; achenes not fleshy-coated, generally glabrous (except <i>Geum</i>)"	11
11	"Style continuous to fruit, if not or inconspicuously hooked then plumose --- leaves 1-pinnately compound"	Geum
11	"Style jointed to fruit, not hooked, not hairy"	12
12	"Leaf (sub)palmately to ternately compound"	13
12	"Leaf +- 1-pinnately to subpalmately compound"	16
13	"Receptacle in fruit strawberry-like (enlarged, red, fleshy); stolons generally present; petals white or yellow; leaves ternately compound"	14
13	"Receptacle in fruit not strawberry-like; stolons 0; petals +- yellow; leaves pinnately, palmately, or ternately compound"	15
14	"Petals yellow; flowers 1 from axils of leaves on stolons; hypanthium bractlets generally wider than sepals"	"Duchesnea {Duchesnea indica var. indica}"
14	"Petals generally white; flowers 1--several from axils of basal leaves, stolons leafless; hypanthium bractlets narrower than sepals"	Fragaria
15	"Stamens 5; petals +- 1 mm; leaflets 3, generally 3-toothed at tip"	"Sibbaldia {Sibbaldia procumbens}"
15	"Stamens 10--25; petals (2)4--20 mm; leaflets 3--7, generally > 3-toothed"	Potentilla
16	"Petals dark red, elliptic to +- ovate, << sepals"	"Comarum {Comarum palustre}"
16	"Petals yellow to white, elliptic to obcordate (linear), < to > sepals"	17
17	"Style fusiform, attached below fruit middle"	Drymocallis
17	"Style slender throughout or widest near base, generally attached below fruit tip"	18
18	"Hypanthium cup-like, +- flat-bottomed; filaments generally +- flat, often forming tube; petals white or +- pink"	19
18	"Hypanthium +- shallow, if cup-like, not flat-bottomed; filaments generally thread-like, not flat (except +- flat in <i>Ivesia argyrocoma</i> var. <i>argyrocoma</i>), not forming tube; petals white to yellow"	20
19	"Stamens 10; leaflets 2--15 per side; CA-FP, GB"	Horkelia
19	"Stamens 20; leaflets 15--35 per side; c&s SNH, SNE"	Horkeliella
20	"Plant generally hanging clump or rosette in vertical rock crevices, +- resin-scented"	Ivesia
20	"Plant not hanging clump or rosette, generally not in vertical rock crevices, resin-scented or not"	21
21	"Leaf generally +- cylindric; leaflets 4--80 per side; pistils 1--8(20); stamens 5--20(40); petals 1--5(7) mm, linear to obovate or round"	Ivesia
21	"Leaf generally +- flat; leaflets 2--8(13) per side; pistils generally > 10; stamens 20--25; petals (2)4--20 mm, generally +- widely obcordate"	Potentilla
22	"Leaves deeply lobed (generally to midrib) or compound"	23
22	"Leaves simple, lobed (deeply so only in <i>Crataegus monogyra</i>) or unlobed"	32
23	"Ovary generally inferior, chambers 1--5; styles 1--5; fruit pome"	Sorbus
23	"Ovary superior, chamber 1; style 1; fruit achene or follicle"	24
24	"Pistils generally 10--many"	25
24	"Pistils 1--6"	28
25	"Petals yellow; hypanthium bractlets 5; style attached near fruit base"	"Dasiphora {Dasiphora fruticosa}"
25	"Petals white to red; hypanthium bractlets 0 (5 in <i>Fallugia</i>); style attached at fruit tip"	26
26	"Plant not prickly; leaves pinnately lobed, rusty-scaly abaxially, margins rolled under; style plumose in fruit; e DMtns"	"Fallugia {Fallugia paradoxa}"
26	"Plant generally prickly; leaves pinnately to palmately compound, not rusty-scaly, margins not generally rolled under; style short-hairy to +- glabrous in fruit; generally CA-FP, GB"	27
27	"Leaves pinnately compound; hypanthium urn-shaped; fruit not on spongy receptacle, generally enclosed in fleshy hypanthium"	Rosa
27	"Leaves palmate-lobed or -compound; hypanthium flat to saucer-shaped; fruit on spongy receptacle, not enclosed by hypanthium (aggregate raspberry- or blackberry-like)"	Rubus
28	"Leaves opposite; 1&deg; leaflets 5--14 cm; inflorescence generally flat-topped; trunk bark peeling in strips; ChI"	Lyonothamnus
28	"Leaves alternate or clustered; 1&deg; leaflets or lobes generally < 5 cm; inflorescence not flat-topped; trunk bark generally not peeling in strips; mainland"	29
29	"Leaf 3--9-lobed; inflorescence generally 1-flowered; styles in fruit 2--6 cm, plumose"	Purshia
29	"Leaf (1)2--3-pinnate- or -ternate-dissected or -compound; inflorescence raceme or panicle; styles in fruit generally << 1 cm, not plumose"	30
30	"Stem +- prostrate to decumbent; plant < 2 dm; leaves ternately dissected, not glandular, not strong-smelling"	"Luetkea {Luetkea pectinata}"
30	"Stem ascending to erect; plant > 2 dm; leaves pinnately compound, glandular, strong-smelling"	31
31	"Pistil 1(2); ovule 1; fruit achene; leaves 2--3-pinnately compound"	Chamaebatia
31	"Pistils 4--5; ovules generally >= 2; fruit follicle; leaves (1)2-pinnately compound"	"Chamaebatiaria {Chamaebatiaria millefolium}"
32	"Ovary inferior or 1/2-inferior, chambers generally 2--5; fruit a pome with generally papery core, occasionally drupe-like with 1--5 stones"	33
32	"Ovary superior (sometimes hidden in funnel- or urn-shaped hypanthium), chamber generally 1; fruit not a pome"	40
33	"Stem armed with thorns"	34
33	"Stem generally not armed (thorny or not in <i>Malus</i>, <i>Pyrus</i>)"	35
34	"Leaves +- ovate, deciduous, generally +- lobed above middle, toothed; larger leaves > 3 cm wide; fruit red to black"	Crataegus
34	"Leaves generally oblanceolate, narrowly oblong, narrowly obovate, or narrowly elliptic, +- evergreen, unlobed, entire to toothed; larger leaves < 2.5 cm wide; fruit orange to red"	Pyracantha
35	"Leaf generally sharp-toothed"	36
35	"Leaf entire, minute-gland-toothed, or above middle toothed"	38
36	"Inflorescence many-flowered panicle; petals < 4 mm; fruit 5--10 mm diam"	"Heteromeles {Heteromeles arbutifolia}"
36	"Inflorescence few-flowered cluster; petals 10--15 mm; fruit >= 10 mm diam"	37
37	"Fruit generally +- spheric, flesh not gritty"	Malus
37	"Fruit generally +- obovoid, flesh gritty"	"Pyrus {Pyrus communis}"
38	"Leaves +- clustered on short-shoots, petiole +- 0"	"Peraphyllum {Peraphyllum ramosissimum}"
38	"Leaves evenly distributed on branches, twigs, petiole > +- 0"	39
39	"Leaves generally serrate above middle, deciduous; fruit a pome of 2--5 papery segments, generally blue-black"	Amelanchier
39	"Leaves entire, deciduous, or evergreen; fruit a pome, drupe-like with 2--5 stones, orange to red"	Cotoneaster
40	"Leaf veins palmate"	41
40	"Leaf veins pinnate"	43
41	"Leaf blade 3(5)-lobed above middle, generally wedge-shaped, margin not toothed, rolled under; flowers 1"	Purshia
41	"Leaf blade generally 3--7-lobed below middle, not wedge-shaped, margin +- toothed, +- flat; flowers in cluster of several to many"	42
42	"Petals 2.5--3 mm; pistils 1--5 (if 3--5, fused below middle); inflorescence umbel-like cluster, not flat-topped; fruit follicles"	Physocarpus
42	"Petals 4--30 mm; pistils 5--150; inflorescence raceme- or panicle-like cyme, +- flat-topped; fruit fleshy-coated achenes (aggregate +- raspberry-like)"	Rubus
43	"Plant matted, scapose; rosettes many --- generally on limestone"	Petrophytum
43	"Erect shrub or tree, not scapose; rosettes 0"	44
44	"Leaves opposite or in opposite clusters"	45
44	"Leaves alternate or in alternate clusters"	46
45	"Shrub 2--20 dm; petals 0 (1--5); pistil 1(2); fruit achene; SNE, D (especially DMtns)"	"Coleogyne {Coleogyne ramosissima}"
45	"Tree 40--150 dm; petals 5; pistils 2; fruit follicle; ChI"	Lyonothamnus
46	"Pistil generally 1"	47
46	"Pistils generally 2--6"	50
47	"Hypanthium cup- to urn-shaped, deciduous in fruit; style not tapered to stigma; fruit drupe"	Prunus
47	"Hypanthium +- funnel-shaped to obconic, persistent in, +- enclosing fruit; style tapered to stigma; fruit achene or achene-like"	48
48	"Hypanthium 0.6--3.2 mm; petals 1.5--2.5 mm; inflorescence many-flowered panicle; leaf linear to oblanceolate or sickle-shaped, margin not rolled under"	Adenostoma
48	"Hypanthium 2--14 mm; petals 0 or 6--8 mm; inflorescence 1--18-flowered cluster; leaf linear to round, margin generally rolled under"	49
49	"Petals 0; leaf toothed or not, lobes 0"	Cercocarpus
49	"Petals 6--8 mm, white to cream; leaf generally not toothed, lobes 3--9"	Purshia
50	"Leaf generally entire; inflorescence raceme, pendent; flowers unisexual, occasionally bisexual; fruit drupes"	"Oemleria {Oemleria cerasiformis}"
50	"Leaf lobed or toothed; inflorescence umbel-like cluster, panicle, or flower 1, spreading to erect; flowers bisexual; fruit achenes or follicles"	51
51	"Leaf generally widest above middle, margins with 3--9 lobes, generally 0 teeth, +- strongly rolled under; flowers 1"	Purshia
51	"Leaf generally widest at or below middle, margins with +- 0 lobes, generally with teeth, not rolled under; flowers generally 3--many"	52
52	"Inflorescence umbel-like cluster, flowers generally 3--5; petals 4--6 mm; stamens +- 50, sepals +- toothed"	"Neviusia {Neviusia cliftonii}"
52	"Inflorescence raceme or panicle, flowers many; petals 1.5--2 mm; stamens generally < 50, sepals not toothed"	53
53	"Petals generally white; hypanthium saucer-shaped; stigma +- 2-lobed; fruit 5 achenes"	Holodiscus
53	"Petals pink to rose; hypanthium obconic to bell-shaped; stigma head-like; fruit 5 follicles"	Spiraea