SPERMATOPHYTA— POIvYGONACEAE 



423 



Fig. 201. Water Pepper (.Polygonum Hydro- 

 piper). Troublesome to sheep. (After Hoch- 

 stein.) 



mostly greenish; stamens 4 or sometimes 6; ochreae cylindrical, fringed with 

 short bristles; style short, 2-3 parted; achene lenticular or 3-angled, dull, 

 granular. 



Poisonous properties. This species and the door yard knot weed (P. avi- 

 culare) are said to be troublesome to sheep 



CENTROSPERMAE 



Herbs mostly with perfect flowers; calyx present; corolla, when present, 

 polypetalous ; ovary superior; perisperm present; embryo coiled, curled or an- 

 nular; fruit not an achene. Generally fleshy plants, many found in saline soils. 

 It includes the families Chenopodiaceae, Amaranthaceae, Nyctaginaceae, Phy- 

 tolaccaceae, Caryophyllaceae, Portulacaceae and others. The last named contains 

 the garden pussley (Portulaca oleracea), the moss pink ( P. grandiflora) , and 

 the bitter root (Lewisia rediviva). The family Aisoaceae also of this order, 

 contains the New Zealand spinach {Tetragonia expansa), and the ice plant 



