98 SALICACEAE 



21. TIPULARIA Nutt. 

 1. Tipulaiia unifolia (Muhl.) B.S.P. Crank-fly Orchis. (Man. 

 p. 304; I. F. / ii4t-) In woods, Vt. to Mich., Fla. and La. — Pennsyl- 

 vania : DeIyAWARE, near Darby. 



Subclass 2. DICOTYLEDONES. 



Series 1. CHORIPETALAE. 



Order 1. PIPERALES. 



Famii^y I. SAURURACEAE I/iudl. Lizard's-taii. Family. 



1. SAURURUS L. 



1. Saurutus cemuus L. Lizard's-Tail. (Man. p. 307 ; I. F.y. //.^5. ) 

 In swamps and streams, Out., to Minn., Conn., Fla. and Tex. — Pennsyl- 

 vania : Lancaster ; Franklin ; Huntingdon ; Mifflin ; York ; 

 Chester ; Delaware ; Allegheny. 



Order 2. SALIC ALES. 

 Family i. SALICACEAE Lindl. Willow Family. 



Bracts incised : disk cup-like : stamens usually 10 or more, rarely 7-8 : stigmas 

 elongated and expanded : winter buds with several scales. i. Populus. 



Bracts entire : disk merely i or more axillarj' glands : stamens less than 10 : 

 stigmas short, not expanded : winter buds with i scale each. 2. Salix. 



1. POPULUS L. 



Petioles terete or channeled. 

 Leaf-blades persistently white tomentose beneath, 3-5-lobed. 



I. P. alba. 

 Leaf-blades glabrous or nearly so when mature, not lobed. 



Stigmas dilated : leaf-blades acuminate : anthers about as broad as long : 



capsules less than i cm. long. 2. P. candicans. 



Stigmas narrow ; leaf-blades blunt : anthers about twice as long as broad : 

 capsules over i cm. long. 3. P. helerophylla. 



Petioles much flattened laterally. 

 Leaf-blades ovate or suborbicular. 

 Leaf-blades crenate-dentate : bracts usually surpassing the pistil. 



4. P. treniuloides. 

 Leaf-blades sinuate-dentate : bracts usuallj' shorter than the pistil. 



5. P. ^randidentata. 

 Leaf-blades deltoid or somewhat reniform. 



Stamens 6-8 : branches erect. 6. P. dilatata. 



Stamens 50 or more : branches spreading. 7. P. delioides. 



1. Populus alba L. White or Silver-lEaf Poplar. (Man. p. 

 308; I. F. y. 1/64.) In yards and along roadsides, N. B. to Va. Native of 

 Eu. and Asia. — Pennsylvania: L.\ncaster ; Delaware ; ALLEGHENY. 



2. Populus candicans Ait. Balm of GilEad. (Man. p. 309.) In 

 woods and fields, N. B. to N. J., west to Minn., mostly escaped from cult. 



