Revised identification key for the woody species of Euphorbia
Stems unarmed; without stipular spines
Leaves shorter than 10 cm, all leaves of same colour
Stem and leaves uniformly red, leaves in whorls of three, petiole
almost as long as blade.......E. cotoniifolia
Stem and leaves green, leaves alternate, petiole much shorter than
blade
Leaves shorter than 2 cm, less than 2 mm broad, branches
straight, mostly leafless
(leaves early
deciduous)......................................................................E.
tirucalli
Leaves longer than 3 cm, more than 2 cm broad, branches
zigzag, mostly with leaves.......E. tithymaloides
Leaves longer than 10 cm; lower leaves green, upper partly or
uniformally coloured
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Leaves below the inflorescence uniformally coloured (red,
white or yellow); leaves not lobed...E. pulcherrima
Leaves below the inflorescence coloured only at base; leaves
lobed or not
Base of upper leaves pale green or pale white; leaves
lobed or not...............................E. heterophylla
Base of upper leaves red; leaves
lobed......................................................................E.
cyathophora
Stems armed with spines
Spines borne on stem, usually longer than 1 cm; two showy bracts around
cyathium...................E. milii
Spines borne on raised shield, usually shorter than 1 cm, two showy
bracts lacking
Stem rounded, not angled or winged
Shrub wiithout trunk with branches arising from base, smaller
leaves (3-8 cm long)
and longer spines 0.5-1 cm.............E caducifolia
Tree with distinct trunk, leaves 10-25 cm long, spines
shorter than 0.5 cm........................E. nivulia).
Stem angled or winged
Angles not produced into wing, spirally
arranged:....................................................... E.
neriifolia
Angles produced into wings
Wings 3-4
The wings running straight, sinuate, regularly
dentate
Stems green without white
bands....................................................E. antiquorum
Stems white wholly or partially
The stems with white
bands on faces
Apex of stem
not cristate (without crowns at tips)...........E. lactea
Apex of stem
cristate (with crowns at tips)......................E lactea cv. Cristata
The stems uniformly
greyish white...................................... ...E. lactea cv. White
Ghost
The wings running spirally,
...................................................................................E.
tortilis
Wings 5-6,
undulate.....................................................................................................E.
royleana
--
Dr. Gurcharan Singh
Retired Associate Professor
SGTB Khalsa College, University of Delhi, Delhi-110007
Res: 932 Anand Kunj, Vikas Puri, New Delhi-110018.
Phone: 011-25518297 Mob: 9810359089
http://people.du.ac.in/~singhg45/
