1	"Bulbils present"	2
1	"Bulbils absent"	15
2	"Leaves hollow"	3
2	"Leaves solid"	7
3	"Flowers bell-shaped"	4
3	"Flowers not bell-shaped"	5
4	"Inflorescence stalk hollow; flowers yellow-white"	"Allium fistulosum"
4	"Inflorescence stalk solid; flowers white to pink tinged greenish"	"Allium vineale"
5	"Tepals white with a green midvein, star-shaped"	"Allium cepa {Allium cepa Proliferum Group}"
5	"Flowers pink to red"	6
6	"Inflorescence stalk hollow; tepals red-brown, pink to white"	"Allium sphaerocephalon"
6	"Inflorescence stalk solid; tepals white to rose pink with a darker midvein"	"Allium aflatuense"
7	"Leaves 2–5"	8
7	"Leaves generally 5-numerous"	11
8	"Flowers white, sometimes tinged brown, green or pink"	"Allium oleraceum"
8	"Flowers blue, violet or purple"	9
9	"Flowers blue with a darker midvein"	"Allium caeruleum"
9	"Flowers violet to purple"	10
10	"Stamens longer than tepals"	"Allium carinatum"
10	"Stamens shorter than tepals"	"Allium scorodoprasum {Allium scorodoprasum subsp. scorodoprasum}"
11	"Tepals with a darker midvein"	12
11	"Tepals without a darker midvein"	13
12	"Inflorescence stalk hollow"	"Allium cepa {Allium cepa Aggregatum Group}"
12	"Inflorescence stalk solid"	"Allium karataviense"
13	"Flowers star-shaped"	"Allium sativum"
13	"Flowers cup- to bell-shaped"	14
14	"Inflorescence stalk hollow"	"Allium schoenoprasum"
14	"Inflorescence stalk solid"	"Allium ampeloprasum"
15	"Leaves waxy blue"	16
15	"Leaves not waxy blue"	20
16	"Flowers yellow"	17
16	"Flowers white, pink or violet"	18
17	"Flowers bell-shaped"	"Allium flavum"
17	"Flowers star-shaped"	"Allium moly"
18	"Inflorescence stalk not ribbed"	"Allium giganteum"
18	"Inflorescence stalk ribbed"	19
19	"Leaves hairy"	"Allium christophii"
19	"Leaves not hairy"	"Allium stipitatum"
20	"Leaves 1–5"	21
20	"Leaves generally 5 or more"	26
21	"Flowers bell-shaped"	22
21	"Flowers not bell-shaped"	24
22	"Leaves 3–5"	"Allium paniculatum"
22	"Leaves 1–2"	23
23	"Leaves 2 per bulb; tepals white with red midveins"	"Allium zebdanense"
23	"Leaf single per bulb; tepals deep pink"	"Allium unifolium"
24	"Inflorescence stalk 3 sided; leaves linear-lanceolate"	"Allium neopolitanum"
24	"Inflorescence stalk not 3 sided"	25
25	"Leaves ovate, stalked"	"Allium ursinum"
25	"Leaves linear, not stalked"	"Allium scorodoprasum {Allium scorodoprasum subsp. rotundum}"
26	"Leaves flat"	27
26	"Leaves angular or keeled"	35
27	"Flowers nodding"	28
27	"Flowers spreading"	29
28	"Flowers bell-shaped or tubular; tepals blue"	"Allium beesianum"
28	"Flowers cup-shaped; tepals white, deep pink or maroon"	"Allium cernuum"
29	"Flowers cup- or bell-shaped"	30
29	"Flowers neither cup- nor bell-shaped"	34
30	"Tepals yellow-green"	"Allium obliquum"
30	"Tepals pink or purple"	31
31	"Stamens united"	32
31	"Stamens free"	33
32	"Flowers bell-shaped"	"Allium oreophilum"
32	"Flowers cup-shaped"	"Allium atropurpureum"
33	"Tepals white or pink; bulbs ovoid to spherical"	"Allium roseum"
33	"Tepals purple; bulbs oblong, on a short rhizome"	"Allium narcissiflorum"
34	"Leaves basal; tepals white pink or purple; midveins green"	"Allium nigrum"
34	"Leaves on the stems; tepals purple with darker midveins"	"Allium tanguticum"
35	"Inflorescence stalk not angular"	"Allium acuminatum"
35	"Inflorescence stalk angular"	36
36	"Flowers pendulous, bell-shaped; leaves triangular in cross section"	"Allium triquetrum"
36	"Flowers star-shaped; leaves keeled, not triangular in cross section"	"Allium tuberosum"