1	"Plant body consisting of a solitary, unbranched stem"	2
1	"Plants with branching stems"	3
2	"Stems columnar, to 1 m tall, with 13-17 longitudinal ribs and curved spines"	"Euphorbia columnaris"
2	"Stems globose, to 4 cm in diameter, smooth, spineless"	"Euphorbia turbiniformis"
3	"Plants trees to 6 m tall or more"	4
3	"Plants shrubs no more than 5 m tall and branching from the base, or herbs"	7
4	"Spine-shields joined to form a continuous horny ridge along the branch angles"	"Euphorbia Bally E 309"
4	"Spine shields separate"	5
5	"Branches cylindrical and spineless or or obtusely 3-angled with spines to 12 mm long"	"Euphorbia robecchii"
5	"Branches usually acutely 4-angled with spines to 5 mm long"	6
6	"Branches irregularly constricted into segments 15-25 cm long; spine-pairs 1-1.5 cm apart; capsules about 8 mm long and 12 mm wide"	"Euphorbia ingens"
6	"Branches regularly constricted into segments 5-15 cm long; spine-pairs about 1 cm apart; capsules about 15 mm long and 20 nn wide"	"Euphorbia abyssinica"
7	"Branches deeply 3-6-winged, constricted into segments"	8
7	"Branches terete, 3-angled, or ribbed, not segmented"	11
8	"Branches 3-winged"	9
8	"Branches 4-6 winged"	10
9	"Branches to 12 cm wide; spines 4-8 cm long"	"Euphorbia breviarticulata"
9	"Branches to 3.5 cm wide; spines to 1.5 cm long"	"Euphorbia carteriana"
10	"Shrubs to 1.5 m tall"	"Euphorbia ballyi"
10	"Shrublets with spreading branches or plamts weakly erect and to 50 cm tall"	"Euphorbia leontopoda"
11	"Capsules subsessile"	12
11	"Capsules exserted on recurved pedicels"	29
12	"Spines paired"	13
12	"Spines single, with or without forked tips"	21
13	"Branches subterete; spine-shields widely separated in 3-4(-5) longitudinal series"	14
13	"Branches 4-10-angled or ribbed; spines shields joined or separated only by the flowering eyes"	16
14	"Branches trailing, often rhizomatous"	"Euphorbia reptans"
14	"Branches densely tufted"	15
15	"Branches blue-green; spine shields decurrent, in 4(-5) longitudinal series"	"Euphorbia gillettii"
15	"Branches yellow-green; spine shields triangular, in 3 spiral series"	"Euphorbia fascicularis"
16	"Cyathia bright yellow; primary cyathium in each cluster with 5 involvucral glands"	17
16	"Cyathia yellowish brown or red; primary cyathium with 4 glands"	19
17	"Spine-shields distinctly separated at the flowering eyes; spine-pairs 8-10 mm apart;"	"Euphorbia galgalana"
17	"Spine -shields joined or scarcely separated at the flowering eyes; spine-airs 3-8 mm apart"	18
18	"Branches erect, 4(-6) angled"	"Euphorbia nigrispina"
18	"Branches spreading, 5-7-angled"	"Euphorbia gelderensis"
19	"Branches 4-angled; spines 5-10 mm long"	"Euphorbia migiurtinorum"
19	"Branches with 4-10 ribs; spines 0-3 mm long"	20
20	"Branches 4-8-ribbed; spines 0.5-3 mm long; cyathia yellowish-brown"	"Euphorbia erlangeri"
20	"Branches 5-10-ribbed; spines not visible to the naked eye; cyathia crimson"	"Euphorbia cryptospinosa"
21	"Spines with forked tips"	22
21	"Spines without forked tips"	24
22	"Plants sparingly branched shrubs 1-3 m tall; branches sharply 4-angled"	"Euphorbia glochidiata"
22	"Plants densely branched herbs 0.25-0.5 m tall"	23
23	"Plants with an obvious main stem, to 30 cm tall and 5 cm think, producing numerous slender branches and with conspicuous dark green stripes"	"Euphorbia schizacantha"
23	"Plants with main stem obscured by spreading branches, uniformly pale green"	"Euphorbia margaretae"
24	"Main stem 5-20 cm tall, usually obscured by dense or tangled branches, at least on mature stems"	25
24	"Main stem very short, with branches"	26
25	"Branches 6-8 mm thick, desnely tufted; spines slender"	"Euphorbia myrioclada"
25	"Branches 8-15 mm thick, spreading, sparingly rebranched and often tangled[?] or tufted; spines robust"	"Euphorbia xylacantha"
26	"Branches few, 1.5-2.5 cm thick, erect; plants erect, to 30 cm tall"	"Euphorbia erigavensis"
26	"Branches many, 6-15 mm thick, spreading, 2-30 cm long"	27
27	"Branches up to 3 cm long and 8 mm thick"	"Euphorbia immersa"
27	"Branches to 15 (rarely 30) cm long; 8-15 mm thick"	28
28	"Branch teeth rounded into tubercles; spine shields oblong-triangular; spines robust"	"Euphorbia xylacantha"
28	"Branch teeth acute; spine-shieds elongated, slender; spines slender"	"Euphorbia actinoclada"
29	"Plants shrubs 50-250 cm tall, branching from the base; spine-shields joined to form a horny margin along the angles"	30
29	"Plants herbs, to 25 cm tall  or, if taller, then branching compact, forming ""cushons""; spine-shields separate, occasionally with branch angles hardening between them"	32
30	"Branches loosely spreading, sharply 4-angled; spines to 70 mm long"	"Euphorbia longispina"
30	"Branches stiffly erect, 4-5-angled; spines 5-15 mm long"	31
31	"Plants shrubs at least 100 cm tall; spine-pairs robust, 8-15 mm apart"	"Euphorbia inculta"
31	"Plants shrubs up to 50 cm tall; spine-pairs bristle-like, 4-6 mm apart"	"Euphorbia setispina"
32	"Branches spreading, rebrnching irregularly"	33
32	"Branches tufted or ""cushion""-forming or semi-prostrate and sparingly rebranched"	34
33	"Branches 4-angled, glossy-green"	"Euphorbia colubrina"
33	"Branches terete, 4-6-ribbed, purplish grey"	"Euphorbia holmesiae"
34	"Plants with a globose main stem 3-5 cm in diameter, eventually producing branches 1-5(-120 cm long in 5-7 tightly packed vertical series"	"Euphorbia horwoodii"
34	"Plants with a non-globose main stem or branching early in development"	35
35	"Plants no more than 8 cm tall and in diameter or with creeping branches to 8 cm long"	36
35	"Plants at least 10 cm tall or with compact branching and at least 10 cm in diameter or with a semi-prostrate stem at least 15 cm long"	38
36	"Branches densely dufted, with tubercles in 5 spiral series; spines up to 10 mm long"	"Euphorbia eilensis"
36	"Branches few, with tubercles in 6-8 series; spines 1.5-4 mm long"	37
37	"Branches spreading"	"Euphorbia baradii"
37	"Branches creeping"	"Euphorbia sp Thulin & Abdi Dahir 6704"
38	"Stems semi-prostrate, sparingly branched"	39
38	"Branches densely tufted or forming compact ""cushions"""	42
39	"Branches 1.5-2 cm thick; tubercles in 5 series; spine pairs robust 7-10 mm apart"	"Euphorbia prona"
39	"Branches 1-1.5 cm think; tubercles in 7-10 series; spine-pairs 3-7 mm apart"	40
40	"Plant bases (lowest 10 cm of main stem) with tightly interlaceds spines and prickles, each 4-6 mm long"	"Euphorbia dasyacantha"
40	"Plants without tightly interlaced spines and prickles"	41
41	"Branches up to 30 cm long; tubercles in 7 series; spine-shields oblong, 2-5 mm long"	"Euphorbia inaequispina"
41	"Brnches to 10 cm long; tubercles forming 8-10 longitudinal ridge; spine-shields suborbicular, about 2 mm in diameter"	"Euphorbia johannis"
42	"Branches with tubercles in 5(-8) series"	43
42	"Branches with tubercles forming 5-17 longitudinal toothed ridges separated by deep grooves"	49
43	"Branches with tubercles in 3 loosely spiralled series"	"Euphorbia elburensis"
43	"Branches with tubercles in 5 or more series"	44
44	"Branches 7-10 mm thick, densely tufted from the plantbase"	45
44	"Branches 10-25 mm thick, densely rebranching from a short stem to form a compact ""cushion'"	46
45	"Branches about 10 mm thick; tubercles in 5 series, forming tesselations; spines 10-15 mm long, robust"	"Euphorbia ellenbeckii"
45	"Branches about 7 mm thick; tubercles in 5 longitudinal series separated by shallow grooves; spines 2-26 mm long, slender and flexible"	"Euphorbia imparispina"
46	"Branch tubercles very prominent; spines to 25 mm long"	"Euphorbia atrox"
46	"Branch tubercles shallow to rounded; spines 8-20 mm long"	47
47	"Spines 15-20 mm long; spine-shields obovate"	"Euphorbia perarmata"
47	"Spines 8-12 mm long; spine-shields suborbicular"	48
48	"Branches 10-15 mm thick; tubercles shallow, in 5 longitudinal series"	"Euphorbia umbonata"
48	"Branches 10-25 mm thick; tubercles prominent in 5-8 tightly spiral series"	"Euphorbia ponderosa"
49	"Branches 5-angled"	"Euphorbia mitriformis"
49	"Branches 6-many angled"	50
50	"Branches 6-9-angled"	51
50	"Branches 10-many-angled"	52
51	"Branches mostly 8-angled; spine-shields oblong-obovate, about 4 mm long and 2 mm wide; spines 0.5-18 mm long, varying on a plant"	"Euphorbia phillipsiae"
51	"Branches mostly 7-angled; spine-shields suborbicular, about 2 mm long and wide; spines up to 1.5 mm long"	"Euphorbia mosaica"
52	"Plants to 30 cm tall; branching usually dichotomous; branches 2-3 cm thick"	"Euphorbia multiclava"
52	"Plants 3-15 cm tallk, branching from near the base, not dichotomously branched; branches 10-25 mm thick"	53
53	"Spines absent but prickles converging to form a single downward-pointing spine 0.5-1.5 mm long"	"Euphorbia sepulta"
53	"Spines variable in lengh, many 0.5-3 mm long interspersed with a few up to 15 mm ling"	"Euphorbia phillipsioides"