DESCRIPTIONS OF SOME COMMON WEEDS 229 



from New Jersey to Illinois, Southern Iowa, South Da- 

 kota, Nebraska and south to Texas and Georgia. 



Campanula Family (Campanulaceae). Herbs with 

 milky juice, alternate leaves ; regular flowers calyx ad- 

 herent to the ovary ; corolla five-lobed, bell-shaped ; 

 stamens five, usually free from the corolla and distinct; 

 style one with hairs near the end ; stigmas two or more ; 

 fruit a capsule, two or more-celled, many seeded ; seed 

 small, anatropous ; embryo straight. Represented by the 

 common harebell (Campanula rotundifolia) and several 

 cultivated species, among them C. rapunculoides. 



Venus' Looking-glass (Specularia perfoliata, (L.) A. 

 D C.). A somewhat hairy annual, with roundish or 

 ovate, clasping leaves, base heart-shaped ; flowers ses- 

 sile, solitary or a few in the axils of the leaves ; calyx in 

 earlier flowers three or four-lobed or parted, in later 

 flowers four or five-lobed ; corolla five-lobed or parted in 

 the later flowers, rudimentary in earlier flowers; ovary 

 three-celled, ovules numerous ; seeds small, lenticular. 

 Common in dry woods, sandy soil from New England 

 to Mexico and Oregon. 



Thistle Family (Compositae, Adans.). Herbs or 

 rarely shrubs ; flowers borne in a close head on the recep- 

 tacle, surrounded by an involucre of a few or many 

 bracts ; anthers usually united into a tube, syngenesious. 

 sometimes caudate ; calyx adnate to the ovary, limb 

 crowning the summit in the form of capillary or plumose 

 bristles or chaff called the pappus; corolla tubular or 

 strap-shaped when tubular, usually five-lobed, ligulate, 

 or bilabiate in one small division of the family; flowers 

 of the head may all be alike, in which case they are called 

 homogamous, or of two kinds (heterogamous) ; bracts or 

 scales often present on the receptacle ; flowers inside the 

 rays are called disk flowers, and a flower without rays is said 

 to be discoid ; the five, or rarely four, stamens are usually 

 united into a tube (syngenesious) ; style two-cleft at the 



