SPURGE FAMILY 35 



a. Stems and leaves with stinging hairs Tragia 



b. Stems and leaves without stinging hair? 



(1) Flowers separate Ditaxis 



(2) Stamen and pistil flowers in a calyx-like 



cup, often bordered by petal-like glands Euphorbia 



Croton Linne 1753 Croton 

 (Gr. kroton, name of the castor-oil plant) 



Stamen flowers with 4-6 united sepals, tiny petals and 5-10 stamens ; 

 pistil flowers with 5-10 united sepals, no petals and a 3-celled ovary with 

 1 ovule in each cell, styles branched, fruit splitting into 2 parts ; flowers 

 monoecious, in small clusters ; leaves more or less silvery-gray with star- 

 shaped hairs ; annual. 

 Leaves oblong-ovate to lance-oblong, entire, silvery C. texensis 



Ditaxis Vahl 1824 

 (Gr. di-, two, taxis, row, from the stamens) 



Stamen flowers with 4-5 united sepals, 4-5 petals, and 4-15 stamens 

 united into a column ; pistil flowers similar as to sepals and petals, ovary 

 3-celled, 1 ovule in each cell, styles branched, fruit splitting into 3 parts ; 

 flowers monoecious, in small clusters ; leaves entire ; perennial. 

 Plant 4-10 in. high ; leaves ovate to oblong, 1-3 cm. 



long, petioled, hairy D. humilis 



Tragia Linne 1753 Tragia 

 (Named for Tragus or Bock, one of the earliest herbalists) 



Stamen flowers with 3-5 united sepals, no petals, and mostly 1-3 

 stamens ; pistil flowers with 3-8 united sepals, 3-celled ovary, 1 ovule in 

 each cell, styles simple; flowers in racemes; leaves toothed, with stinging 

 hairs ; perennial. 

 Plant 4-10 in. high; leaves lance-ovate, 1-5 cm. long T. ramosa 



Euphorbia Linne 1753 Spurge 



( Xamed for the physician Euphorbus) 



PI. 7, fig. 4. 



The apparent flower is really a cluster or involucre, containing several 



tiny flowers, consisting of one stamen each and a single scale, and one 



j pistil flower, with the characteristic 3-lobed ovary ; the 3-lobed fruit projects 



| from the involucre on a stalk; leaves opposite, alternate or wlmrled, entire, 



toothed or lobed, typically with a milky juice; annual, biennial, or perennial. 



