3208 



SPIR^A 



SPIR^A 



INDEX, CONTINUED. 



KEY TO THE SECTIONS. 



A. Inf.. a simple umbel-like raceme: fls. white. 



Section I. CHA&LEDRYON. Species Nos. 1-20. 

 AA. Inf.. compound: fls. white or pink. 

 B. Fls. in corymbs. 



Section II. CALOSPIKA. Species Nos. 21-42. 

 BB. F Is. in panicles. 



Section III. SPIRABIA. Species Nos. 43-55. 



Section I. CHAM^IDRYON. Species Nos. 1-20. 



A. Fls. in sessile umbels with none or very 



small Ivs. at the base or only the lower 



umbels on leafy stalks. 



B. Foliage entire or crenately dentate 



only near the apex, often 3-nerved, 



grayish green 1. hypericifolia 



BB. Foliage dentate or serrate, usually 



penninerved, bright green. 

 c. Shape of Ivs. linear-lanceolate: 



glabrous 2. Thunbergii 



cc. Shape of Ivs. ovate to oblong-lanceo- 

 late: finely pubescent when 

 young. 



D. Umbels on the lower part of the 

 branches stalked. 



E. Lvs. oblqng 3. arguta 



EE. Lvs. obovate 4. multiflora 



DD. Umbels all sessile, 3-6-fld 5. prunifolia 



AA. Fls. in umbel-like racemes on leafy 



stalks. 

 B. Margin of Ivs. entire or crenate or 



dentate only toward the apex. 

 c. Foliage grayish pubescent on both 



sides 6. cana 



cc. Foliage almost glabrous. 



D. Shape of Ivs. elliptic to oblong- 

 lanceolate. 



E. Lvs. penninerved: shoots an- 

 gular 7. alpina 



EE. Lvs. all or partly 3-nerved. 

 F. Shoots striped: Ivs. all 3- 



nerved 8. crenata 



FF. Shoots terete: Ivs. partly 

 penninerved, partly 3- 



nerved 9. pikowiensis 



DD. Shape of Ivs. almost orbicular, 



Yi-l in. broad 10. nipponica 



BB. Margin of Ivs. incisely serrate and 

 often slightly lobed (only in No. 18 

 sometimes entire). 



c. Stamens shorter than or as long as 

 petals; sepals erect or spreading 

 infr. 

 D. Foliage glabrous. 



E. Form of Ivs. orbicular to ovate. 

 F. Apex of Ivs. obtuse. 



G. Lvs. penninerved, ovate... 11. Blumei 

 GO. Lvs. palmately 3-5- 



nerved, orbicular 12. trilobata 



FF. Apex of Ivs. acute 13. Vanhouttei 



EE. Form of Ivs. rhombic-lan- 

 ceolate 14. cantoniensis 



DD. Foliage pubescent, at least be- 

 neath. 



E. Umbels and follicles pubes- 

 cent. 



F. T amentum grayish 15. blanda 



FF. Tomentum yellowish 16. chinensis 



EE. Umbels and follicles glabrous. 17 '. pubescens 

 cc. Stamens longer than petals; sepals 



reflexed. 



D. Shoots terete, often pubescent. ... 18. media 

 DD. Shoots angular, glabrous. 



E. Lvs. doubly and irregularly 

 serrate from below the 



middle 19. chamaedry- 



EE. Lvs. simply serrate, usually [folia 



only above the middle 20. flezuosa 



1. hypericifdlia, Linn. Vigorous shrub, 5 ft. high, 

 with slender arching or upright branches: Ivs. almost 

 sessile, cuneate-obovate to obovate-lanceolate, 3- 

 nerved or with few lateral veins, almost glabrous, %- 

 1J^ in. long: fls. small, white, in sessile umbels; pedicels 

 usually pubescent; petals almost orbicular, usually 

 longer than stamens. April, May. S. E. Eu. to Siberia. 

 Variable species. Var. acuta, Ser. (S. acutifolia, 

 Willd.). Lvs. narrower, oblanceolate : fls. smaller, yel- 

 lowish white; pedicels glabrous; petals obovate, shorter 

 than stamens: fls. somewhat earlier, but less showy. 

 G.O.H. 9. Var. flabellata, Zabel (S. flabellata, Bertol. 

 S. hypericifdlia var. crenata, Boiss. & Buhse). Lvs. 

 obovate to obovate-lanceolate, acute, incisely serrate at 

 the apex or entire on the flowering branches. Var. 

 obovata, Maxim. (S. obovata, Waldst. & Kit.). Lvs. 

 obovate, rounded at the apex, crenate above the middle. 

 S. E. Eu. G.O.H. 11. Var. truncata, Zabel (S. thalic- 

 troldes, Hort., not Pall.). Lvs. broadly obovate to 

 oblong-obovate, truncate and crenately dentate at the 

 apex. Siberia. 



2. Thunbergii, Sieb. Fig. 3660. Shrub, 5 ft. high, 

 with spreading or arching branches: Ivs. linear-lanceo- 

 late, sharply serrulate, 1-1% in. long: fls. pure white, 

 about ^in. across, in 3-5-fld. naked umbels; petals 



3661. Spiraea prunifolia 

 var. plena. ( X Yt) 



obovate, much longer than stamens: follicles with the 

 spreading styles below the apex. April, May. China, 

 Japan. S.Z. 1:69. G.F. 8:84, 85. J.H. 111.47:337. 

 A very graceful early-flowering shrub, the slender arch- 

 ing branches clothed with feathery bright green foliage, 

 turning late in fall to orange or scarlet. Almost hardy, 

 but tips of branches sometimes killed by severe frost; 

 valuable for seaside planting. 



3. arguta, Zabel (S. Thunbergii x S. multiflora). Simi- 

 lar in habit to the former but higher and more vigorous: 

 Ivs. oblong-obovate to oblong-oblanceolate, sharply and 

 sometimes doubly serrate, glabrous at length, 1-1% in. 

 long: fls. pure white, Hin. across, in many-fld. umbels, 

 mostly with small Ivs. at the base; pedicels glabrous; 

 petals broadly obovate, almost twice as long as sta- 

 mens. May. Of garden origin. G.C. III. 22:3; 43:398. 

 Gn. 73, p. 578; 78, p. 82. A.G. 22:633. G.M. 44:385. 



