Vor. I.] ROSE FAMILY. 197 
4. Spiraea Virginiana Britton. Vir- 
ginia Spiraea. (Fig. 1886.) 
S. Virginiana Britton, Bull. Torr. Club, 17: 314. 1890. 
A glabrous much-branched shrub, the branches 
forming wands 1°-4° long. Stipules deciduous 
or none; leaves petioled, oblong or oblanceolate, 
thin, obtuse or acutish at the apex, cuneate or 
rounded at the base, 1%4/-2/ long, 5/’-8’’ wide, 
green above, pale or slightly glaucous beneath, 
entire, or with a few low teeth above the middle; 
flowers white, about 3/’ wide, in terminal com- 
pound corymbs; pedicels and calyx glaucous; 
follicles glabrous. 
On damp rocks, Morgantown, W. Va., to the 
mountains of North Carolina. June. 
Spiraea sorbifdlia, a large shrub with odd-pinnate 
leaves, lanceolate serrate leaflets, and large panicles 
of white flowers, much cultivated for ornament, 
has begun to escape into thickets in the Middle 
States. It is native of Siberia. 
3. ARUNCUS Adans. Fam. Pl. 2: 295. 1763. 
Tall perennial herbs, with large 2-3-pinnate leaves, stipules minute or wanting, and very 
numerous white dioecious flowers in panicled spikes. Calyx mostly 5-lobed. Petals as 
many as the calyx-lobes. Stamens numerous, inserted on the calyx; filaments filiform. 
Pistils usually 3, alternate with the calyx-lobes. Follicles glabrous, at length reflexed, usually 
2-seeded. Seeds minute, not shining. 
Two known species, the following widely dis- 
tributed in the north temperate zone, the other 
Japanese. 
1. Aruncus Aruncus (L.) Karst. 
Goat’s-beard. (Fig. 1887.) 
Spiraea Aruncus L,. Sp. Pl. 490. 1753. 
Aruncus sylvester Kostel. Ind. Hort. Prag. 15. 
Name only. 1844. 
Aruncus Aruncus Karst. Deutsch. Fl. 779. 1880-83. 
Glabrous throughout, stem erect, somewhat 
branched, 3°-7° high. Leaves long-petioled, the 
lower 1° long or more, pinnate, 3-7-foliolate; 
leaflets ovate, lanceolate or oval, thin, stalked 
or sessile, acuminate or acute at the apex, 
rounded, slightly cordate or sometimes nar- 
rowed at the base, sharply doubly serrate or in- 
cised, 1/-3’ long; spikes slender, elongated, 
erect or spreading; flowers 1-2’ wide; follicles 
short. 
In rich woods, mountains of Pennsylvania to 
Iowa, south to Georgia and Missouri. Also on the 
northwest coast from Oregon to Alaska, and in 
northern Europe and Asia. Ascends to 4200 ft. in 
North Carolina. May-July. 
4. PORTERANTHUS Britton, Mem. Torr. Club, 4: 115. 1894. 
[GILLENIA Moench, Meth. Suppl. 286. 1802, Not GirLeNA Adans. 1763. ] 
Erect perennial herbs, with nearly sessile stipulate 3-foliolate or 3-parted leaves, and 
white or pinkish perfect flowers in loose terminal panicles. Calyx cylindric, persistent, nar- 
rowed at the throat, 1c-nerved, 5-toothed, the teeth imbricated, slightly glandular. Petals 5, 
linear-lanceolate, spreading, convolute in the bud, somewhat unequal, inserted on the calyx. 
Stamens 10-20, included; filaments short; anthers large. Carpels 5, villous-pubescent, op- 
posite the calyx-lobes. Ovulesascending; style filiform. Follicles 5, 2-4-seeded. Sceds with 
endosperm. [In honor of Thomas Conrad Porter, Professor in Lafayette College. ] 
A genus of 2 known species, natives of eastern North America, 
Leaflets serrate; stipules subulate, mainly entire. 1. P. trifolialus. 
Leaflets incised; stipules broad, foliaceous, incised. 2. P. stipulatus, 
