\YIITTE OR WHITISH FLOWERS 91 



Arrow-leaved Tear-thumb {Polygonum sagittatum). 

 Buckwheat family. 

 Stem square, generally climbing by backward- 

 bending prickles; flowers very small, pale-rose 

 color or white, in head or dense cluster; leaves 

 arrow-shaped. Low grounds. Summer. 



Halberd-leaved Tear-thumb (Polygonum arijolium). 

 Buckwheat family. 

 Stem square, generally climbing by prickles; 

 flowers very small; leaves halberd-shaped, with 

 long stalks. Low ground. 



Wild Balsa.m Apple {Echinocystis lohaia). Gourd 

 family. 

 Tall annual, climbing by tendrils; flowers axillary, 

 small, generally in racemes, or clusters; leaves 

 thin with 5 lobes; fruit large, green, covered with 

 spines. Rich soil. Summer. 



52. Leaves (neither opposite, wanting, nor from root only) simple, 



flowers in cluster, plant upright, shrub, over 

 5ft., with thorns. 



CocKSPUR Thorn {Crataegus Crus-galli). Rose family. 

 Shrub or small tree; thorns long and slender; calyx 

 urn-shaped, petals 5; leaves thick and shiny, in- 

 versely egg-shaped or lance-shaped. Thickets. 



Hawthorn* {Crataegus coccinea). Rose family. 



Similar to above but thorns stout and leaves thin. 



53. Leaves (neither opposite, wanting, nor from root only) simple, 

 flowers in cluster, plant upright, shrub over 5 ft., without 



thorns, flowers urn- or bell-shaped. 



Great Laurel {Rhododendron maximum). Heath 

 family. 

 Tall shrub; corolla bell-shaped, 1-2^ in. broad; 

 leaves several in. long, thick, pointed. Damp 

 woods. Summer. 



