Spreading Avens

Spreading avens is a tall perennial herb (eight to 20 inches) in the rose family. Its distinctive bright yellow flowers (generally up to 1 inch across) appear from June through September, and fruits form and ripen from August through October.  Spreading avens are sometimes called Appalachian avens or cliff avens, are endemic to a few scattered mountaintops in western North Carolina and eastern Tennessee. It grows on the shallow acidic soils of high-elevation cliffs, outcrops, and steep slopes and on gravelly talus associated with cliffs, often in full sun.

Habitat

Spreading avens grows in pioneer perennial herb communities at high-elevation rocky sites typically above 4,200ft-6,000ft. Occupied sites at higher elevations are surrounded by spruce-fir or by northern hardwoods containing scattered spruce.  This species prefers locations where it is exposed to direct sunlight for at least part of the day and on the shallow acidic soils of high-elevation cliffs, rocky outcrops, steep slopes, and on gravelly talus. 

The soils on which spreading avens grows are generally shallow and acidic (pH 4-5), uniform, dark brown, coarse-loamy, and without distinct horizons. The soil usually collects in the cracks and crevices of the underlying rock. Annual rainfall ranges from 41 to 102 inches but is generally well draining, and temperatures of 5 degrees to 48 degrees Fahrenheit. 

Physical characteristics

Geum radiatum is a perennial herb with basal leaves rising from horizontal rhizomes. Spreading avens display bright yellow flowers approximately 1 inch in across and often reach heights between eight to 20 inches. Flowering occurs from June through September; fruiting occurs from August through October. This species can be distinguished easily from other Southeastern Geum species by its showy yellow flowers and by the large terminal lobes and greatly reduced lateral lobes on the basal leaves 

Lifestyle

Flowering occurs from June through September; fruiting occurs from August through October.

Reproduction

The relative importance of sexual and asexual reproduction to this species is unknown. One could speculate that small units relatively isolated from other units could have started from seed. Population clusters along cracks in the underlying rock would suggest that those individuals originated from rhizomes by asexual reproduction. 

Geography

Southern Appalachians of western North Carolina and extreme eastern Tennessee.

• Morgan, 5. 1980. Species status summary for Geum radiatum Michaux; Species General Information System: species, population, habitat, and threat inventory.
• Massey, J., P. Whitson, and T. Atkinson. 1980 Endangered and threatened plant survey of 12 species in the eastern part of Region IV. USFWS Contract 14-160004-78-108.