rough avens (Geum laciniaum)
SCIENTIFIC SYNONYMS: There are no scientific synonyms for
CONFIRMATION STATUS: Pending confirmation.
TAXONOMY: The currently accepted scientific name of rough avens
is Geum laciniaum Murray. Rough avens blooms a little later than Geum
vernum (spring avens), but a little earlier than Geum canadense (white
avens) and Geum virginianum (pale avens). It can be confused with white
avens. However, rough avens has petals that are shorter than the sepals
and its flowering stalks have coarse spreading hairs. White avens has pet-
als that are as long or longer than the sepals and its flowering stalks are
finely pubescent. Pale avens also has an appearance that is similar to rough
avens. Pale avens has slightly smaller flowers (about 1/3" across) with
cream petals that are much shorter than the sepals. The receptacles of its
flowers are bristly-hairy, while the receptacles of rough avens are hairless
or nearly so.
NATIVE STATUS: Native, United States and Canada.
GENERAL BOTANICAL CHARACTERISTICS:
Habit: This native perennial plant is 1½2½' tall, branching occasionally.
The round stems are light green and covered with coarse spreading hairs.
Leaves: Both basal and cauline leaves are produced; the cauline leaves are alternate, becoming smaller as they ascend the stems. The basal and lower
cauline leaves are oddly pinnate (often with 5 leaflets), while the upper
cauline leaves are trifoliate or simple. The simple leaves and leaflets of the compound leaves are up to 3" long and 2½" across. They are lanceolate to
ovate-oval, coarsely serrated or shallowly cleft along the margins, and
largely hairless. Sometimes the leaves and leaflets are deeply cleft into 2
or 3 lobes. The terminal leaflet is larger in size than the lateral leaflets.
The basal and lower cauline leaves have stout petioles, while the upper
cauline leaves are nearly sessile. At the base of each petiole, there is a pair
of leafy stipules that are cleft or dentate; each stipule is up to ½" long.
Flowers: The upper stems individually terminate in 1-3 flowers; some-
times single flowers are produced from the axils of the upper leaves. Each
flower develops from a stalk (peduncle) up to 3" long; this stalk is covered
with coarse spreading hairs. Each flower is about ½" across, consisting of
5 petals that are white or cream, 5 triangular green sepals, and several
stamens surrounding a large cluster of green carpels with elongated styles.
The petals are shorter than the sepals. The anthers are usually dull yellow
or tan. The receptacle of the flower (underneath the carpels) is hairless or
nearly so. There is no noticeable floral scent.
Fruit/Seeds: Each flower is replaced by a spheroid cluster of achenes with
elongated styles that are hooked at their tips. This fruiting cluster is about
¾" across; it is initially green, but eventually turns brown.
Roots: The root system consists of a taproot and rhizomes; vegetative off-
sets are often formed.
REGENERATION PROCESS: Rough avens propogates itself by reseed-
ing and vegetative spread by rhizomes.
HABITAT TYPES: Habitats include savannas, thickets, woodland borders,
and moist meadows. Sometimes it is found in thickets and prairie remnants
along railroads and roadsides.
SITE CHARACTERISTICS: Rough avens prefers partial sun, moist to
mesic conditions, and a fertile loamy soil. Full sun and light shade are
SEASONAL DEVELOPMENT: The blooming period occurs from late
spring to mid-summer and lasts about a month.
GENERAL DISTRIBUTION: Rough avens is primarily a species of the
eastern United States and Canada. It generally occurs from South Caro-
lina north to New Brunswick, and west through Tennessee to Kansas and
Nebraska (the fartherest west it naturally occurs). It can be found in the
Ohio Valley and in the upper mid-west into Ontario. In general it is not
found in most of the Gulf states, Florida to Texas (Alabama being the ex-
ception), the southwest, Great Plains, Rocky Mountain states, and far west-
ern and northwestern states. Ontario is as far west as it naturally occurs in
SKY MEADOWS DISTRIBUTION: To be determined.
IMPORTANCE AND USES: Little information is available about floral
-faunal relationships for this species. They are probably similar to those of
Geum canadense (white avens). The nectar and pollen of the flowers prob-
ably attract small bees, wasps, and flies. The achenes with hooked styles
can cling to the fur of mammals, feathers of birds, and clothing of humans;
by this means, they can be distributed across considerable distances.
Crooked Run Valley