Provided below is a list of the Euphorbia species of Texas. I have provided a little additional information on the species outside of section Anisophyllum and sect. Alectoroctonum. I may write a separate journal post for these sections and have already written one for subgenus Esula (which can be found here). Links: iNaturalist Texas species list (not up to date), BONAP, Flora of North America.

Subgenus Esula

E. lathyris - Leaves clearly opposite, forming an X shaped pattern going up the stem; plants bluish-green
E. spathulata - Serrated leaves, no horn-like appendages on the oval glands, and warty fruits
E. texana - Just like E. spathulata but with smooth fruits
E. helioscopia - Like E. texana but typically with around 5 pleiochasial branches instead of 3 (the main branches of the inflorescence)
E. peplus - Winged fruits
E. roemeriana - Partially fused dichasial bracts (the bracts that are held in pairs)
E. brachycera - Large perennial plants usually with some triangular-ovate bracts (hard to separate unless you actually see the plants or a picture of the plants)
E. peplidion - Dichasial bracts +/- broadly lanceolate with acute apices
E. longicruris - Dichasial bracts imbricate with rounded apices, not mucronate
E. austrotexana - Leaves narrow, linear to oblanceolate or narrowly lanceolate
E. tetrapora - Dichasial bracts mucronate; stems erect, unbranched at the base
E. helleri - Dichasial bracts mucronate; stems ascending, branched at the base; lower leaves notably emarginate, leaves except dichasial bracts spathulate or oblanceolate.

Section Poinsettia

Glands appendaged
E. bifurcata - Plants annual, bracts not linear, broadest at the apex; glands with petaloid appendages, 1(-3).
E. exstipulata - Plants annual, bracts linear to lanceolate to nearly ovate or rhombic, typically broadest at the middle or base; glands with petaloid appendages, 4 per cyathium.
E. eriantha - Plants perennial, bracts green and linear; glands obscured by fuzzy appendages, 4 per cyathium.
Glands unappendaged. Lower leaves alternate, stems glabrous
E. cyathophora - Plants annual, tall in bloom, bracts typically red basally (often completely green in central Texas), linear or broader; glands oblong, 1 per cyathium.
E. heterophylla - Plants annual, tall in bloom, bracts green (sometimes whitish basally); glands circular.
E. radians - Plants perennial, very short in bloom, bracts pink; glands oblong, 1-5 per cyathium.
Glands unappendaged. Lower leaves opposite, stems hairy
E. davidii - Seeds slightly angled, tubercles unevenly distributed.
E. dentata - Seeds essentially round in crossection, tubercles evenly distributed.

Section Alectoroctonum

E. antisyphilitica
E. bicolor
E. bilobata
E. corollata
E. discoidalis
E. graminea
E. hexagona
E. innocua
E. marginata
E. strictior
E. wrightii

Section Anisophyllum

E. abramsiana
E. acuta
E. albomarginata
E. arizonica
E. astyla
E. bombensis
E. capitellata
E. carunculata
E. chaetocalyx
E. chaetocalyx triligulata
E. cinerascens
E. cordifolia
E. cryptorubra
E. fendleri
E. geyeri
E. geyeri wheeleriana
E. glyptosperma
E. golondrina
E. hirta
E. humistrata
E. hypericifolia
E. hyssopifolia
E. indivisa
E. jejuna
E. laredana
E. lata
E. maculata
E. micromera
E. missurica
E. meganoesos
E. nutans
E. ophthalmica
E. parryi
E. perennans
E. prostrata
E. revoluta
E. serpens
E. serpillifolia
E. serrula
E. setiloba
E. simulans
E. stictospora
E. theriaca
E. theriaca spurca
E. velleriflora
E. vermiculata
E. villifera

Posted on September 16, 2018 10:29 PM by nathantaylor