18 DIANDRIA. MONOOYNIA. 



in the warm regions of India, of Peru, Mexico, and th© 

 West- Indies. About 47 species are natives of JSox'th and 

 South America. 



£6. COLLINSONIA. Z. (Knot-root, Horse- 

 weed.) 



Calix bilabiate, above 3-toothecl, below bifid. 

 Corolla much longer than the calix, somewhat 

 funnel-formed, unequally 5-lobed; the lower 

 lobe longer, lacerately fimbriate (or fringed). 

 Stamina 2, sometimes* 4. Seeds 4, 3 of them 

 mostly abortive. 



Leaves large. Flowers in terminal panicles, yellowish 

 or inclining to violet, with the 2 fertile stamina es*. 

 tended beyond the corolla. 



Species. 1. C.Cayiadensis. 2.tuberosa. o.scubra. As.ova- 

 lis. 5. miisata. 6 pimctata. E. 7. verticillata. 



The C. punctata has 2 barren filaments, and the C- 

 ariisata is tetrandrous. (a North American genus.) In thi» 

 genus the stamens are observed alternately to approacti 

 the style. 



B, Corolla superior. 

 ff ft Flowers complete* 



27. CIRCJEA. L. (Enchanter's Nightshade.) 

 Calix shavtf 2 parted. Petals 2. Stigma eniar- 

 ginate. Capsule ovate, hispid, 2-celled, not 

 opening; cells 1 -seeded. 



Herbs; with opposite leaves; flowers alternate, in ter-, 

 minal spikes. 



Species. 1. C. hctetiana, ^ canadensis 2. alpina? This 

 does aot well agree with the European species. 



If If f Flowers incomplete^ 



j88. X.EMNA. L, (Duck-weed,) 



Calix t)f one entire leaf. Stamens alternately 

 developed, seated upon the ovarium at its base| 

 9tyle cylindric, stigma funuel form. CapsuU 2 

 to 4 -seeded. 



