CLASS IX. ORDER I. 169 



three principal segmeats of the calyx furnished with a keel, but 

 not winged. Flowers all summer in waste and cultivated 

 ground. — Annual. 



Polygonum scandens. L. Climbing Polygonum. 



Leaves heart shaped ; stem twining, angular ; seg- 

 ments of the calyx winged. 



Stem smooth, climbing. Leaves petioled, heart shaped, with 

 a deep sinus, acuminate. Branches axillary. Flowers in long 

 leafy racemes. Calyx much larger than in the last species, with 

 three broad, membranous expansions, corresponding to the an- 

 gles of the seed.— Cambridge. — August. — Perennial. 



Polygonum cilinode. 3Ix. Running Polygonum. 



Leaves heart shaped ; stipules subacute, ciliate at 

 base, stem angular, running or climbing, roughish ; 

 calyx obtusely carinate. 



Stem purplish, running or twining, with a ring of hairs at each 

 joint; calyx of the fruit without wings. — About woods, &c. — 

 July, August. — Annual. 



Polygonum fagopyrum. L. Buckwheat. 



Racemes panicled, stem erect, unarmed ; leaves 

 heart sagittate, angles of the seed equal. 



Common buckwheat is sure to remain as a weed about lands 

 where it has been cultivated. — June. — Annual. 



Class IX. ENNEANDRIA. Nine stamens. 

 Order I. MONOGYNIA. One style. 



180. Laurus. Calyx none ; corolla six parted, re- 

 sembling a calyx; nectary three glands, surround- 

 ing the germ, each ending in two bristles ; inner fila- 

 ments with two glands each ; drupe one seeded. 

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