Based on species already posted and expected one a simple key for woody
species of Euphorbia is presented
Perhaps we can expand the key for woody succulent species of Euphorbia as
under:
Stems unarmed; without stipular spines
Leaves shorter than 10 cm, uniformally green
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; uniformally or partly coloured
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...............................................................................................................E.
milii
Spines borne on raised shield, usually shorter than 1 cm
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/
