16 



SALICACEAE— MORACEAE— GERANIACEAE 



2. Leaves and stipules without glands 



a. Leaves glabrous on both sides when mature 



(1) Leaves narrow, linear-lanceolate; low shrub 



(2) Leaves broader, lanceolate to ovate 



(a) Leaves oblong-lanceolate, merely acute 



(b) Leaves acuminate 



b. Leaves pubescent or tomentose below 



(1) Leaves oblong; low bog shrub 



(2) Leaves broadly lanceolate, or oblanceolate 



(a) Leaves elliptic to lanceolate 



(b) Leaves oblanceolate 

 x. Leaves 5-10 cm. long 

 y. Leaves 2-5 cm. long 



Populus — Poplar, Cottonwood, Aspen 



(L. populus, a poplar-tree) 

 PI. 5, fig. I : 1, 2 



1. Crown cylindric ; branches erect 



2. Crown rounded ; branches spreading 



a. Leaves with strongly flattened petioles 



(1) Leaves coarsely wavy-toothed 



(2) Leaves more finely crenate-toothed 



(a) Leaves round or ovate, short-pointed 



(b) Leaves truncate at base, long-pointed 



b. Leaves with round or channeled petioles 



Malvales Mallow Order 



.9. jhnidtilis 



S. discolor 

 S. nigra 



S. Candida 



S. bebbidna 



S. Ini mil is 

 S. tristis 



P. nigra itdlica 



P. grandidentdta 



P. tremuloides 

 P. deltoides 

 P. balsamifera 



Moraceae — Mulberry Family 

 Trees with simple leaves and usually a milky juice; sepals 4-5, petals 0, stamens 4-5, ovary 

 1-celled ; flower syncarpous, apetalous, hypogynous. 



Morns — Mulberry 



(Gr. morea, mulberry-tree) 

 Tree with milky sap and dentate leaves M. rubra 



Ulmaceae — Elm Family 

 Trees with alternate simple serrate leaves ; sepals 3-9, petals 0, stamens 3-9, ovary 1-celled, 

 stigmas 2; flowers perfect to polygamous, syncarpous, apetalous, hypogynous. 



I. Fruits winged, in clusters 



II. Fruits globose, single 



l'lmus — Elm 



(L. ulmus, elm-tree) 

 PI. 6, fig. H : 1, 2, 3 



1. Bud-scales densely brown hairy ; samara not ciliate 



2. Bud-scales smooth ; samara ciliate 



a. Some of the twigs with corky lines ; sides of fruit hairy 



b. None of the twigs with corky lines ; sides of fruit smooth 



Celtis — Hackberry 



(L. celtis, lotus-tree) 

 PI. 6, fig. G : 1, 2, 3 

 Tree with ridged bark, and simple serrate leav< - 



Geraniales Geranium Order 



L'lmus 

 Cell is 



U. fulva 



U. racemosa 

 U. americdna 



C. occidentdlis 



Geraniaceae — Geranium Family 

 Herbs with deeply cut leaves and perfect flowers : sepals 5, petals 5. stamens 5-10, ovary 5- 

 celled ; flower syncarpous. apopetalous. hypogynous, regular. 



I. Stamens with anthers 10 Geranium 



II. Stamens with anthers 5 Erodium 



