harvestlice (Agrimonia parviflora)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

COMMON NAMES:

manyflowered groovebur

harvestlice

harvest-lice

small flowered agrimony

harvestlice agrimony

swamp agrimony

southern agrimony

 

A variety of common names is currently being used in text and

websites.

SCIENTIFIC SYNONYMS: There are no scientific synoyms for

Agrimonia parviflora.

CONFIRMATION STATUS: Pending confirmation.

TAXONOMY: The currently accepted scientific name for harvist lice

is Agrimonia parviflora Aiton.

NATIVE STATUS: Native, United States and Canada.

GENERAL BOTANICAL CHARACTERISTICS:

 

Habit: This native perennial wildflower is 2½–5' tall. The stout central

stem is unbranched, terete, and light green, reddish green, or brownish

green; it is covered with long hairs that are white or light brown. Along

each stem, there are widely spreading alternate leaves.

 

Leaves: The leaves are odd-pinnate and up to 2' long and ½' across; each

leaf has 9-17 primary leaflets and smaller secondary leaflets. The second-

ary leaflets are located between pairs of primary leaflets. Individual prim-

ary leaflets are 2-3" long and about one-third as much across; they are nar-

rowly lanceolate, narrowly oblanceolate, or elliptic with wedge-shaped bot-

toms and acute tips. Leaflet margins are coarsely dentate. The upper sur-

face of each leaflet is yellowish green and hairless, while the lower surface

is short-pubescent. Secondary leaflets are similar to the primary leaflets,

but they are much smaller in size (less than 1" long). Both the petiole and

rachis of each compound leaf are pubescent; quite often, they have sparse

long hairs. At the base of each leaf, there is a pair of large stipules that are

fan-shaped and either coarsely dentate or cleft with pointed lobes. 

 

Flowers: The central stem terminates in a long spike-like raceme about ¾–

2½' long. Robust plants also produce secondary racemes from the axils of

the upper leaves that are shorter than the terminal raceme. These racemes

are usually more or less erect, although longer racemes sometimes bend

sideways to become nearly horizontal with the ground. The central stalk

of the raceme is light green, terete, and short-pubescent. Numerous small

flowers about ¼" across occur along the length of the raceme on short stalks

about 1/8" long. Individual flowers consist of a tubular green calyx, 5 yel-

low petals, about 10 stamens, and a central pistil. The tubular calyx is tur-

binate in shape and 10-ribbed.

 

Fruit/Seeds: The flowers are replaced by 1-2 seeded fruits about ¼" across.

These small fruits have numerous hooked prickles along the upper rims of

their persistent calyxes. Immature fruits are green, while mature fruits are

brown.

 

Roots: The root system is fibrous and rhizomatous. Vegetative colonies of

plants are often produced.

REGENERATION PROCESS: Swamp agrimony propogates itself by re-

seeding and vegetative spread.

 

HABITAT TYPES: Habitats include openings in floodplain woodlands,

swamps, soggy thickets, gravelly seeps, riverbottom prairies and prairie

swales, and roadside ditches. The preceding habitats can be either sandy

or non-sandy.

SITE CHARACTERISTICS: Swamp agrimony prefers full sun to light

shade, moist conditions, and loamy, silty, gravelly, or sandy soil. It tolerates temporary flooding during the spring.

SEASONAL DEVELOPMENT: The blooming period occurs from mid-

to late summer and lasts about 1-2 months.

GENERAL DISTRIBUTION: Harvist lice is found throughout the east-

ern United States, from Georgia to New England (excluding Maine, Ver-

mont and New Hamphire). It extends westward through the Ohio Valley

and the Gulf Coast States (except Florida) to Texas and northward to

South Dakota and Minnesota. It also occurs only in Ontario. It does not

naturally occur in the southwest, far west, Rocky Mountain, or northwest

states or provinces.

SKY MEADOWS DISTRIBUTION: To be determined.

IMPORTANCE AND USES: The nectar and pollen of the flowers attract

small bees and flower flies (Syrphidae). Larvae of the midge, Contarinia agrimoniae, feed on the flower buds, flowers, and developing seeds of Agri-

monia spp. and other species in the Rose Family, while an aphid, Macro-

siphum agrimoniellum, sucks juices from the flowering stems. Insects that

feed on the foliage of Agrimonia spp. include larvae of a sawfly (Fenella

nigrita), larvae of a Gelechiid moth (Anacampsis agrimoniella), and larvae

of a Tischeriid moth (Coptotriche agrimoniella). Because the foliage is bit-

ter-tasting and high in tannins, it is usually avoided by mammalian herbi-

vores. The bur-like fruits can cling to the fur of mammals, the feathers of

birds, and the clothing of humans, which spreads the seeds to new locations.

 

 

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