14 MINNESOTA TREES AND SHRUBS 



clusters, leaves mostly long- 



petioled Cornus: dogzvood 270 



s. Leaf-scars distinct 



(r) Leaf-scars very small and flat, 



petioles short Ligustrum: privet 115 



(s) Leaf-scars round 

 h. Leaves smooth, flower- and 



fruit-clusters terminal Syringa: lilac 111 



i. Leaves hairy or pimply beneath, 

 flower- and fruit-clusters lat- 

 eral Chionanthus : fringe-tree 115 

 (y) Leaves toothed 

 m. Leaves mostly in whorls of three Hydrangea : hydrangea 183 

 n. Leaves in twos, strictly opposite 



(m) Buds hidden by the petiole Philadelphus: syringa 181 



(n) Buds not hidden 

 r. Leaves coarsely toothed Viburnum', viburnum 280 



s. Leaves finely serrate 



(r) Bark ridged, roots white Euonymus: burning bush 195 



(s) Shrubs .7-1.3 m. high; bark not 

 ridged 

 h. Leaf-scars running together to 



form a ring Diervilla: bush-honeysuckle 294 



i. Leaf-scars round, distinct Forsythia 113 



(t) Shrubs 2-5 m. high, petioles 



wide and glandular Viburnum : black haw 280 



y. Leaves alternate or fascicled 



(x) Thorny shrubs with fascicled leaves Berberis: barberry 48 



(y) Shrubs or vines with alternate leaves 

 m. Leaves entire 



(m) Leaves silvery Elaeagnus: silverberry 209 



(n) Leaves not silvery 

 r. Thorny vines 



(r) Leaves oblong, pinnate veined Lycium : matrimony I'ine 106 



(s) Leaves cordate, more or less 



parallel veined Smilax: smilax 300 



s. Smooth shrubs 



(r) Tall shrub; leaves crowded at 



tips of twigs Cornus: dogwood 270 



(s) Low shrubs 

 h. Bark very tough Dirca : leaiherwood 208 



i. Bark not especially tough 



(h) Leaves resinous below Gaylussacia : huckleberry 95 



(i) Leaves not resinous Vaccinium : huckleberry 97 



n. Leaves toothed or serrate 



(m) Twining vine Celastrus: biltersivcct 195 



(n) Shrubs 

 r. Leaves with three distinct veins Ceanothus: redroot 199 



s. Leaves pinnately veined 



(r) Leaves unequal at base Hamamelis: witch hazel 193 



(s) Leaf bases equal 

 h. Shrubs with spines or thorns 

 (h) Spiny shrubs, about 1 m., 

 leaves smooth and glossy 



above Cydonia : Japanese quince 146 



(i) Thorny shrubs, taller, leaves 



not glossy Crataegus: hawthorn 154 



i. Shrubs without thorns 



(h) Leaves blunt to rounded at 

 tip 

 p. Leaves fragrant Myrica : sweet gale 268 



