SPIRAEA 10'7 



small, round, continuous. Buds small, solitary or collaterally 

 multiple, sessile, globose to fusiform, with about 6 scales. Leaf- 

 scars alternate, half-round or crescent-shaped, minute; bundle- 

 trace 1. Inflorescence paniculate or corymbose, persistent through 



the winter. 



a. Inflorescence-vestiges paniculate 



b. Stems puberulent or glabrous 



c. Branchlets of panicle puberulent 



or tomentulose 1. S. alba 



c. Branchlets of panicle glabrous 2. S. latifolia 



b. Stems very wooily 3. S. tomentosa 



a. Inflorescence-vestiges corymbose 



b. Stems pubescent 4. S. japonic a 



b. Stems glabrous 



c. Stems simple or nearly so 5. S. corymbosa 



c. Stems much -branched 6. S. virginiana 



1. S. alba Du Roi. Meadowsweet. Wild Spiraea. . Pipe stem. 

 Erect shrub, 0.3-2 m. high; twigs tough, yellowish-brown, more 

 or less angled, pubescent, at least in the paniculate inflorescence. 

 Low ground, Quebec and Vermont to Saskatchewan, south to Mis- 

 souri, Ohio, and in the mountains to North Carolina (Fig. 125). 



2. _S^ latifolia (Ait. ) Borkh. Meadowsweet. Erect shrub 3-12 

 dm. high, with tough yellowish-brown stems; panicles mostly open- 

 pyramidal, 0. 5-3 dm. long, the branchlets glabrous. Low grounds, 

 Newfoundland to Michigan, south in the mountains to North Caro- 

 lina (Fig. 126), 



3. ^ tomentosa L. Hardhack. Steeplebush. Stems angled, 

 1-2 m. high, pubescent with rusty wool; buds solitary, ovoid, 

 short, with several exposed scales. Low grounds. Prince Edward 

 Island to Manitoba, south to Georgia and Arkansas (Fig. 127). 



4. S. japonica L. f. Japanese Spiraea. Stems 1. 5 m. high or 

 less, with gray or dingy inflorescence; twigs terete; inflorescence 

 corymbose. Introduced from Asia, spreading from cultivation into 

 thickets and somewhat naturalized (Fig. 128). 



5. S. corymbosa Raf. Corymbed Spiraea . Stems erect, less 

 than 1 m. high; twigs terete, glabrous, bright red-brown; buds 



