426 MONOECIA POLYANDRIA. 



the margin ; perianth single, deeply 4-parted ; style 1 ; stig. 23 

 taps. 2 3-lobed, 2 3-celled; cells 1 -seeded. 



373. ALNUS. Sterile Fl. Ament composed of 3-flowered, cuneiform 

 truncate receptacles ; cal. the scales of the amcnt, 3-lobed ; cor. 4- 

 parted. Fertile Fl. Scales of the ament 2-flowered, subtrifid; cor. 0; 

 seed compressed, wingless. 



374. BOEHMERIA Sterile Fl. Cal. 4-parted; cor. 0; nectary 0. 

 Fertile Fl. Cal. and cor. 0; seed 1, compressed. 



375. URT1CA. Sterile Fl. Cal. 4-leaved; cor. ; nectary (abortive 

 germen 1) central, mostly cyathiform. Fertile Fl. Cal. 2-leaved; 

 pericarp 1-seeded, shining. 



PENTANDRIA. 



376. AMARANTHUS. Sterile Fl. Cal 3 5-leavcd ; cor. ; slam. 

 35. Fertile Fl. Cal. 3 5-leaved ; cor. ; styles 3 ; caps. 1-celled, 

 opening transversely all round; seed 1. 



377. XANTHIUM. Sterile Fl. Cal. imbricate ; anthers approximate, 

 but not united ; recept. palaceous. Fertile Fl. Calyx a 2-leaved 

 involucrum, 1-flowered ; cor. ; drupe ? dry, muricate, 2-clefl ; nut 

 2-celled. 



378. AMBROSIA. Sterile Fl. Calyx 1-leaved ; anthers approximate, 

 but not united ; recept. naked. Fertile Fl. Calyx 1-leaved, entire or 

 5-toothed, 1-flowered ; cor. ; nut formed from the indurated calyx, 

 1-seeded. 



HEXANDRIA. 



379. ZIZANIA. Sterile Fl. Calyx ; corolla 2-valved, subawned. 

 Fertile Fl. Calyx 0; c.or. 2-valved, cucullate, awned: style 2-parted ; 

 seed 1, invested by the corolla. 



POLYANDRIA. 



380. MYRIOPHYLLUM. Sterile Fl. Calyx 4-cleft ; petals 4, cadu- 

 cous ; stem. 4, 6, or 8. Fertile Fl. Calyx 4-leaved ; petals 4 ; stig. 

 4, pubescent; styles 0; nuts 4, subglobose, 1-seeded. 



381. SAGITTARIA. Sterile Fl. Cal. 3-leaved ; pet. 3; stamens 

 definite. Fertile Fl. Calyx 5-leaved ; petals 3 ; germens numerous ; 

 pericatfis aggregated, 1-seeded, not opening. 



382. Q.UERCUS. Sterile Fl. in a loose ament ; calyx mostly 5-cleft ; 

 cor. ; slam 5 10. Fertile Fl. Involucrum cup-shaped, scaly ; 

 cal. incorporated with the germen, 6-lobed ; germen 3-celled ; 2 ot 

 the cells abortive ; style 1 ; stig. 3 5 ; nut (acorn) 1-celled, coria- 

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

 involucrum. 



383. CORYLUS. Sterile Fl. in a cylindrical ament, its scales 3-clefl ; 

 verianth ; stam. 8 ; anth. 1-celled. Fertile Fl. Cal. obsolete ; 

 germ, several ; stig. 2 ; nut ovate, surrounded with the enlarged 

 coriaceous and scaly involcurum. 



384. FAGUS. Sterile Fl. in a globose ament ; calyx 5 6-cleft, cam- 

 panulate ; stam. 5 12. Fertile Fl. 2. Jnvolucrum 4-lobed, prickly ; 

 cal. single, 4 5-cleft ; styles 3 ; wit l-seeded, inclosed in the en- 

 larged echinate involucrum. 



