256 NORTH AMERICAN FLORA [VOLUME 22 
Plant 12-20 dm. high, much resembling the preceding; leaflets 2-7 cm. long, broader 
and shorter, ovate, abruptly acuminate with a short, narrow acumination, dark-green above, 
paler beneath, often more hairy, usually rounded at the base and sharply doubly serrate; 
petals of the staminate flowers narrower, spatulate and more distinctly clawed, white; 
petals of fertile flowers greenish-white and slightly smaller; follicles about 3 mm. long 
and 1 mm. wide, very shining. 
TYPE LOCALITY: Austria. 
DISTRIBUTION : A native of Europe, cultivated in this country and rarely escaped in the east- 
ern and central states. 
ILLUSTRATIONS : Pall. Fl. Ross. pl. 26, Fl. Deuts. ed. 5, pl. 2564. 
3. Aruncus pubescens Rydberg, sp. nov. 
Stem 1-2 m. high; lower leaves compound as in the preceding two species or ternate 
with the divisions pinnately 5-foliolate; leaflets 3-10 cm. long, when mature firmer than 
the other American species, dark-green and rather dull, ovate, short-acuminate at the apex, 
acute or rounded at the base, more evenly and less distinctly doubly serrate than in the rest, 
glabrous above, rather copiously hairy beneath; panicle 1-4 dm. long, its branches 3-10 
cm. long; petals of the staminate flowers obovate, hardly 1 mm. long, scarcely clawed, 
white; those of the pistillate flowers slightly smaller; follicles about 2 mm. long and % 
mm. wide. 
Type collected in rich woods, Peoria, Illinois, in July, 1903, F. ZH. McDonald (herb. N. Y. 
Bot. Gard.). 
DISTRIBUTION: Woods, from Illinois and Iowa to Oklahoma, Arkansas, and southwestern 
Virginia. 
4. Aruncus allegheniensis Rydberg, sp. nov. 
?.Spiraea Aruncus hermaphrodita Michx. Fl. Bor. Am. 1: 294. 1803. 
2? Spiraea Aruncus americana Pers, Syn. Pl. 2: 46. 1806. 
? Spiraea americana Steud. Nom. Bot. 1: 805. 1821. 
? Aruncus americanus Raf. Sylva Tell. 152; hyponym. 1838. 
Aruncus sylvestris americanus Maxim. Acta Hort. Petrop. 6: 170. 1879. 
Plant 1-2.5 m. high, glabrous; leaves compound as in 4. acuminatus, but the lower 
divisions of the lower leaves often again ternate; leaflets thin, shining, 3-10 cm. long, ovate 
with a short acumination at the apex, usually acute or the terminal rounded at the base, 
sharply doubly serrate, glabrous or nearly so on both sides; inflorescence 1-3 dm. long, with 
spreading branches 3-10 cm. long; flowers lax; petals white, obovate to oblanceolate, claw- 
less; follicles about 2 mm. long and 1 mm. thick. 
Type collected near Baltimore, Maryland, in 1867, P. V. LeRoy (herb. Columbia Univ.). 
DISTRIBUTION : Mountains, from Pennsylvania to Georgia, Alabama, and Kentucky. 
5. Aruncus kamchaticus (Maxim.) Rydberg. 
Aruncus sylvester kamchatica Maxim. Acta Hort. Petrop. 6: 170. 1879. 
Plant 1 m. high or less, glabrous or nearly so throughout; leaves twice to thrice ter- 
nate; leaflets thin, broadly ovate, abruptly acuminate with a short, slender acumination, 
often oblique at the base, 3-6 cm. long, more or less deeply laciniate and sharply toothed ; 
inflorescence short, less than 1 dm. long; branches short, 1-5 cm. long, densely fiowered ; 
staminate flowers much larger than the pistillate; petals broadly obovate, in the latter 
scarcely 1 mm. long; follicles about 2 mm. long and 1 mm. wide. 
TYPE LOCALITY : Kamchatka, near Petropavlovski. 
DISTRIBUTION: Island of Attu, Alaska; also in Kamchatka and the Kurile Islands. 
Tribe 3. SORBARIEAE. Shrubs or perennial herbs, with alternate pin- 
nately dissected leaves and persistent stipules. Infloresence paniculate or 
cymose. Hypanthium hemispheric, campanulate, or turbinate, bearing 10- 
50 stamens. Pistils normally 5, distinct, opposite to the sepals. Endosperm 
present, not scant. : 
Petals obovate or spatulate, imbricate ; carpels united at the base; leaves 
pinnately compound. 
Follicles dehiscent to the base on both sutures; leaves simply pinnate. 7, SCHIZONOTUS. 
