Aruncus dioicus
Rosaceae subfam. amygdaloideae
bride's feathers, buck's-beard, goat's-beard, sylvan goatsbeard
leaflets green to gray-green, 6–15 cm, base subcordate to attenuate, apex acute to long-acuminate.
alternate, sometimes opposite, simple, sometimes pinnately compound;
stipules present or absent.
sepals 1 mm;
petals 0.5–1.5 mm, apex acute to obtuse;
stamens 1.5–2 mm, filaments slender, ± equal, anthers versatile;
styles [0.2–]0.3–0.8 mm.
torus absent or minute;
carpels 1–5(–8), distinct or +/- connate (Maleae), free or +/- adnate to hypanthium (many Maleae), styles distinct or +/- connate (some Maleae);
ovules (1 or)2(–5+), collateral, clustered, or biseriate.
follicles aggregated or not, capsules, drupes aggregated or not, aggregated drupelets, pomes, or aggregated nutlets, rarely achenes or aggregated achenes;
styles persistent or deciduous, not elongate (elongate in Gillenieae).
1.5–2(–2.5) mm.
= 8, 9, 15, 17.
Aruncus dioicus
Rosaceae subfam. amygdaloideae
Varieties 14 (4 in the flora).
Aruncus dioicus is superficially similar to Astilbe biternata (Saxifragaceae), false goat’s-beard, which is endemic to the southern Appalachian Mountains. Both species produce tall, dioecious plants with biternately to bipinnately compound leaves and plumelike terminal panicles with many, relatively small white, unisexual flowers, and may grow side by side. Aruncus dioicus is more widespread and may be readily distinguished by its unlobed rather than 3-lobed terminal leaflets, flowers with 20 rather than 10 stamens, and 3 carpels reflexed in fruit rather than 2 erect carpels. See T. L. Mellichamp (1976) for an analysis of this remarkable example of convergent evolution.
Aruncus dioicus is striking and is grown in gardens throughout North America. It is variable throughout the temperate and subarctic regions of the Northern Hemisphere, especially in China and Japan. H. Hara (1955) recognized the following varieties that are found in the flora area.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Cyanogenic glycosides are usually present in Amygdaloideae; sorbitol is present.
The name Amygdaloideae Arnott (1832) has priority over Spiraeoideae Arnott (1832), used by D. Potter et al. (2007), because Amygdalaceae (1820) is an earlier conserved name.
Tribes 9, genera 55, species ca. 1300 (9 tribes, 38 genera, 361 species, including 20 hybrids, in the flora)
(Discussion copyrighted by Flora of North America; reprinted with permission.)
1. Follicles 1.5–2.4 mm; styles 0.3–0.8 mm; seeds 1.5–2 mm | → 2 |
1. Follicles 2.5–5 mm; styles 0.3–0.5 mm; seeds 1.8–2.5 mm | → 3 |
2. Follicles 1.5–2 mm; leaf surfaces glabrous or slightly hairy; s Appalachians and eastward. | var. dioicus |
2. Follicles 1.6–2.4 mm; leaf surfaces densely hairy; w of Appalachians. | var. pubescens |
3. Follicles 2.5–5 mm; Alaska and Yukon to n California. | var. acuminatus |
3. Follicles 2.5–3 mm; introduced, ne United States. | var. vulgaris |
- Local floras:
BC, 
OR, 
WA - Local Web sites:
CalFlora, CalPhotos, 
Flora NW, 
Go Botany, 
IL Wildflowers, 
MD Biodiversity, 
MI Flora, 
MO Plants, 
PNW Herbaria, Turner Photog. 
WildflowerSearch
iNaturalist (observations)
USDA Plants Database- LBJ Wildflower Center
- SEINet
- Plants of the World Online
- Encyclopedia of Life
- Wikipedia
- Google Image Search
