258 MONCEC. MONAND. 



of them abortive. Style]. Stigmas 3. Nut (acorn) 1 -celled, 

 1 -seeded, surrounded at the base by the enlarged, cup-shaped 

 involucre. 



21. CORYLUS. Barren Fl. in a cylindrical catkin, its scales 3- 

 cleft. Perianth 0. Stam. 8. Anthers 1 -ceiled. 



Fertile FL Perianth obsolete. G&rmens several, surround- 

 ed by a scaly involucre. Stigmas 2. Nut 1 -seeded, surround- 

 ed at the base with the enlarged^ united, coriaceous scales of 

 the involucre. 



20. CARVINUS. Barren FL in a cylindrical catkin ; its scales 

 roundish, ciliated at the base. Stam. 8 20. 



Fertile FL in a lax catkin; its scales large, foliaceous, 3- 

 lobed, 1 -flowered. Involucre 0. Perianth of 1 leaf, urceolate, 

 6-dentate, incorporated with the 2-celled germen, of which 

 1 cell is abortive. Styles 2. f Nut ovate, striated, 1-seeded. 



19. BETULA. Barren Fl. in a cylindrical catkin, its scales 3- 

 flowered. Perianth 0. Stam. 10 12. 



Fertile Fl. Scale of the catkin imperfectly 3-lobed, 3-flow- 

 ered. Perianth. Styles 2. Germens compressed, 2-celled, 

 1 abortive. Nuts compressed^ with a membranaceous margin, 

 1-seeded. 



14. ARUM. Spat ha of 1 leaf, convolute at the base. Perianth 0. 

 Spadix with germens at the base. Stain, (sessile) near the 

 middle of the spadix, which is naked above. Berry 1 -celled, 

 1-seeded, 



6. MONADELPHIA. 



22. PJNUS. Barren Fl. in crowded racemose catkins ; its scales 

 peltate, bearing 2 1 -celled, sessile anthers. ' Perianth 0. 



Fertile FL in an ovate catkin ; its scales closely imbricated, 

 2- flowered. Perianth 0. Pericarp 1-seeded, terminated by 

 a long winged appendage, and covered by the imbricated 

 scales forming a cone (strolilus). 



(Typha. Ord. TRIANDR.) 



1. MONANDRIA. 



1. ZANNICHELLIA. 



1 . Z. palustris (horned Pondweed) , anthers 4-celled, stigmas en- 

 tire, pericarps toothed on the back. Light/', p. 534. E. B. 

 t. 1844. 



HAB. Ditches and stagnant waters. Fl. Aug. Q. 

 Floating. Stems long, filiform, branched. Leaves opposite, linear, 

 entire. Flowers axillary, from a membranaceous bractea. Fertile 

 JJ. upon a very short stalk, from the base of which arises a single- 

 naked anther, upon a long white filament. 



