Taxonomic history:
   1753: Linnaeus described this species as Euphorbia tirucalli in Species Plantarum, 1st ed., p. 452.
   today: The current name for this species is Euphorbia tirucalli L.

original Latin diagnosis
Euphorbia inermis subnuda fruticosa filiformis erecta, ramis patulis determinate confertis.

English translation
Euphorbia unarmed, somewhat naked. shrubby, filiform, [and] erect; [and] with branches spreading [and] determinately packed closely together.

English translation with commentary

Euphorbia	Euphorbia
unarmed,	intermis - nominative singular feminine of group B adjective inermis, -is, -e; modifies Euphorbia
somewhat naked,	subnuda - nominative singular feminine of group A adjective subnudus, -a, -um; modifies Euphorbia
shrubby,	fruticosa - nominative singular feminine of group A adjective fruticosus, -a, -um; modifies Euphorbia
filiform,	filiformis - nominative singular feminine of group B adjective filiformis, -is. -e; modifies Euphorbia
[and]	[added for smoother reading]
erect;	erecta - nominative singular feminine of perfect passive participle of third conjugation verb erigo, erigere, erexi, erectum; modifies Euphorbia
[and]	[added for smoother reading]
with branches	ramis - ablative plural of second declension masculine noun ramus, -i
spreading	patulis - ablative plural masculine of group A adjective patulus, -a, -um; modifies ramis
[and]	[added for smoother reading]
determinately	determinate - adverb; modifies confertis
packed closely together.	confertis - ablative plural masculine of perfect passive participle pf fourth conjugation verb confercio, confercire, confersi, confertum; modifies ramis