CLASSES, DIVISIONS, AND OEDEES. 



69. Santalacece. Perianth superior, 3 5-lobed. Stam. 

 35, opposite perianth-lobes. Ovary 1-celled ; ovules 

 several, pendulous from apex of central placenta 365 



70. AristolochiacecB. Perianth superior, tubular above, 

 3-lobed, or with a dilated irregular limb. Stam. 6 12. . 366 



71. Empetracea. Dioecious. Perianth of hypogynous 

 scales imbricate in several rows. Stam. 3, free. Ovary 

 superior, 3 9-celled. Ovules solitary. A small prostrate 

 heathlike shrub 366 



72. Euphorbiacece. Mon- or di-oecious. Perianth 3- 

 parted or 0. Stam. 1 or more. Ovary superior, 2 3- 

 lobed and -celled ; each cell with 1 2 suspended ovules. 

 Caps, opening with elasticity. In Euphorbia many fl., 

 each of one naked stamen, surround a pendulous 3-lobed 

 naked ovary, enclosed by a calyx-like involucre 367 



73. Ceratophyllacece. Monoecious. Perianth of many 

 divisions. Stam. many, sessile; anth. 2-celled. Ovary 

 superior, 1-celled. Style 1. Submerged plants with 

 inconspicuous fl. and multifid leaves 371 



74. Callitrichacece. Monoecious. Perianth 0, but often 

 2 white bracts. Stam. 1 ; filament long ; anth. 1-celled. 

 Ovary 4-angled, 4-celled. Styles 2. Fr. of 4, 1-seeded, 

 indehiscent carpels. Aquatic plants 371 



75. Urticacece. Mon- or di-cecious (rarely perfect). 

 Perianth inferior, 4 5-parted ; in fern. fl. tubular, notched. 

 Stam. 45. Style filiform or 373 



76. Cannabinacece. Dioecious. Perianth inferior, of 5 

 sepals in male, open and hidden in scales of catkin in 

 female. Stam. 5. Styles 2, long. Long twining plant . 374 



77. Ulmacece. Fl. 2-sexual, not in catkins. Perianth 

 inferior, bellshaped, 4 8-cleft. Stam. 4 8, on tube, op- 

 posite lobes. Ovary 1 2-celled. Styles 2. Fr. dry, 

 flat, winged. Trees. L. alternate, distichous. Stip. de- 

 ciduous 374 



78. Amentiferce. Mon- or di-oecious. Males in catkins. 

 Fern .-perianth 0, or adherent. Fr. bony or membranous 



(or drupaceous in Myricd). Trees or shrubs 375 



Division 5. GYMNOSPEEME^E. 



79. Conifer a. Anth. and ovules on the scales of sepa- 

 rate catkins or cones. Trees or shrubs. 390 



