74 Spring Flora of Ohio. 



Ai-lan'-thus glan-du-lo'-sa Desf. Chinese Tree of Heaven. — Cultivated 

 and occasionally escaped. 



XLII. Order PO-LYG-A-LA'-CE-/E. MILKWORT FAMILY. — Flowers 



irregular, hypogj-nous, stamens 4-8, diadelphous or monadelphous. 



1. Genus PO-LYG'-A-LA. — Flowers very irregular; 3 of the sepals 

 small, petals 3, stamens 6 or 8; bitter, low plants. A large genus, 

 most of our species blooming late. 



Po-lyg'-a-la pau-ci-fo'-li-a Willd. Fringed Polygala. — Flowers showy, 



rose-purple (rarely white), conspicuously crested; flowering stems 3^ 

 in. high. 



Po-lyg'-a-la sen'-e-ga L, Senega Snake-root. — Flowers white, in a 

 solitary close spike; several stems from thick and hard knotty root- 

 stocks. 



XLIII. Order EUPHORBIA -CE-/E. SPURGE FAMILY.— Herbs with 



milky juice; staminate and (single) pistillate flowers enclosed in a 

 cal5rx-like involucre; ovary 3-celled. 



1. Genus EU-PHOR'-BI-A. — Flowers monoecious, included in a cup- 

 shaped, 4 to 5-lobed involucre resembling a calj-x or corolla and usually 

 bearing large, thick glands (with or without petal-like margins) at its 

 sinuses ; fertile flower solitary in the middle of the involucre consist- 

 ing of a o-lobed and 3-celled ovary. 



Eu-phor'-bi-a ob-tu-sa'-ta Ph. Spurge. — Erect, 1-2 ft. high; leaves 

 oblong and spatulate, upper ones cordate at base, floral ones ovate. 



Eu-phor'-bi-a cy-par-is'-si-as L. Garden Spurge. — Stems densely 

 clustered, 6-10 in. high; stem-leaves linear, crowded, the floral heart- 

 shaped. Escaped from cultivation. 



Eu-phor'-bi-a cotn-mu-ta'-ta Englm. Spurge. — Stems branched from 

 a commonly decumbent base, (5-12 in. high; leaves obovate, the upper 

 all sessile, the floral ones roundish, dilated, broader than long, umbel 

 3-forked. 



XIJV. Order CAL-LIT-RI-CHA'-CE-yE. WATER STARWORT FAMILY. — 



Aquatic plants; leaves opposite; flowers axillary, monoecious, destitute 

 of proper floral envelopes. 



