EXOOENS. 57 



Tribe 9. — Ovarian cell 1-ovuled. (^ calyx valvate. Monotixis. Fls. 

 fP, cymose, 9 iii centre, diohlamyd. ; i^ mouochlamyd. Shrubs, heath- 

 like. Australia. 



Tribe 10. — Ovarian cell 1-ovuled. (Jcalyxquincuncial. Ricinocar- 

 pus. ris. ^, dichlam^d., sol., 8 species, similar in habit, all Austra- 

 lian, Kosemary-like bushes. 



Tribe 11. — Ovarian cell 2-ovuled. (^ calyx quincuncial. Poran- 

 thera. Fls. ^p, 5-merous, dichlamyd., clustered, involucrate. Sta. 

 quadrilocular, dehiscence porous. Heath-like shrubs. Australia. P. 

 ericifblia, sta., Fig. 168, B. Allied genus: Oldfieldia africdna, ArKi- 

 CAN Teak Tree ; wood valuable. 



Ament Alliance. — Fls. $(f^or ^p, mono- or achlamyd. in catkins or 

 cone-like hds. Ova. free, 1-2-celled. Perisperm (except in Platanus). 

 Trees or shrubs. 



17. Salicaceae. 18. Casuarinaceae. 19. Myricacese. 20. Platana- 

 ceae. 21. Betulaceae. 



Ord. 17. Salicaceae. Willows or Poplars. — Fls. 9 c?! in cat- 

 kins. Perianth or reduced to a disk. Sta. 2-oo. Ova. 1-celled, 

 00 -ovuled. Fr. caps. 2-valved ; sds. comose. Trees, Shrubs, or creep- 

 ing Undershrubs. Lvs. petioled, simple, entire or angular-toothed ; 

 stipule scaly or foliaceous. 2 gen., nearly 300 species. Types only 

 given here : 



1. P6pulus. Poplar. Catkin-scales jagged. Sta. 4^30. Trees of 

 temperate climates, both worlds. Species near 150, all ornamental. 

 A favorite in Eoman gardens, where it was called Arbor populi, the 

 People's Tree. P. balsamifera, Balsam P. 60°-80° high. Lvs. 

 lobed, dentate ; buds resinous ; viir. cdndicans, Balm-oe-Gilead. N., 

 N. W. P. monilifera, Necklace P., Cottokwood. 60°-80° high. 

 Lvs. triangular-cordate ; sds. silky-cottony. Western Vt. to 111. and 

 La. P. anguldta (var. of last ?), larger ; Penn. to Wis., S. P. tremula, 

 Aspen, 60°-90° high. Lvs. round-ovate dentate. Eur. P. graeca, 

 Greek Poplar (W. Eur.) ; and P. grandidentdta, 46° high, P. 

 tremidoides, 40° high (Am. Aspens), are probably varieties of P. 

 tremula. P. alba, Abele Tree, 80°-90° high. Lvs. cordate, den- 

 tate or lobed, snow-white, canescent beneath. Bur. P. fastigidta, 

 LoMBARDT P., 90°-130° high, branches fastigiate ; lvs. round-triangu- 

 lar, pointed; probably a form of P. nigra. Black P., 80°-100° high, 

 branches spreading; both native to Eur., Asia Minor. 



2. Salix. Willow. Catkin-scales entire. Sta. 2-3-5-10. Trees 

 or shrubs, temperate regions both worlds ; loving moisture ; few species 

 arctic. More than 150 species, chiefly in Old World. S. pentdndra. 

 Bay Willow, 25° high, lvs. lanceolate, glossy, deep green, laurel- 

 like; (^ catkins golden, fragrant. Gt. Brit. S. lueida, 15°-20° high, 

 similar. Mid. States, N. Eng., Can, S. niqra, trunk black, 20° high. 

 Can. to Fla. and Ark. S.frdgilis, Brittle W., 60°-80° high. Gt. Biit. 

 S. babylmicn, Babylon W., Weeping W., 60°-80°high, hd. 70°-80° 

 in diam., branches weeping. Cent. Asia, N. Af. S. cinerea, Gray 

 Sallow, 20°-30° high ; S.'edprea, Goat Sallow, 20°-30° high ; wood 

 made into charcoal. Eur. S. alba, 60°-80° high ; lvs. canescent be- 

 neath. Eur., Asia. Var. vitellina, Golden Osier, has bright yellow 

 branches, very handsome. S. vimindlis, Osier, Basket W. Eur. 

 Twigs used in basket-making, as are those of many other species in Am. 

 and Eur. Many dwarf species, both worlds : S. herbdcea, stems l'-2'' 



