Agrimonia parviflora aka Harvestlice
Taxonomy ID: 13589
Agrimonia parviflora, commonly called swamp agrimony, harvestlice or smallflower agrimony, is a herbaceous perennial in the rose family (Rosaceae) native to central and eastern North America. Plants form clumps of slender, hairy stems that rise from long, fibrous roots and reach roughly 1.2 to 2 meters (4 to 6.5 feet) in height, with the tallest individuals approaching 1.8 meters in favorable sites. The foliage is distinctive: alternate, odd-pinnate compound leaves bear up to about 17 main leaflets interspersed with smaller secondary leaflets, all toothed, giving the plant a feathery, almost fern-like silhouette before bloom.
In midsummer, slender wand-like spikes appear at the tops of the stems and along upper branches, carrying many tiny yellow flowers about a quarter-inch across. Each flower has five petals, five sepals and 5–10 stamens, and the species is hermaphroditic and self-fertile while also being visited by bees and various flies for nectar. Bloom typically runs from June into August, with seed maturing from August to September. The fruits are small, ribbed, hooked burs that cling readily to mammal fur, feathers and clothing, the chief dispersal mechanism that gives the plant its "harvestlice" common name.
The species is native from southeastern Canada (Ontario) south through the central and eastern United States, reaching from Maine and the Atlantic coast westward to Texas, South Dakota and Nebraska, and has been introduced in parts of southern Brazil and Argentina. Its preferred habitat is wet to moist ground in swamps, stream and river banks, lake shores, low woodland edges, prairies and roadside ditches, where it tolerates temporary flooding and cold winters down to roughly −33°F (about −36°C). It accepts a wide range of soils, from sandy and silty through loam to clay, and grows on mildly acidic to mildly alkaline ground, with a noted preference for calcareous sites. It performs best in full sun but tolerates light woodland shade.
In the wild, swamp agrimony is generally listed as globally secure, though it reaches its northeastern range limit in New England and is treated as Special Concern in Connecticut and Endangered in Massachusetts. The plant has historic ethnobotanical use as an astringent herbal tea for diarrhea, minor bleeding, wounds and gall bladder complaints, and the burs and roots have been used to address fevers and digestive ailments, though it is generally regarded as a minor medicinal species (rated 2/5 by Plants For A Future) and has no documented edible or industrial uses.
Common names
Harvestlice, Small Flowered Agrimony, Harvestlice AgrimonyMore information about Harvestlice
How difficult is Harvestlice to grow?
Swamp agrimony is undemanding once sited correctly. It accepts virtually any soil texture from sand to clay, tolerates a broad pH range, withstands extreme cold and seasonal flooding, and self-sows when conditions suit, so the main effort is choosing a sunny, moisture-retentive spot rather than ongoing care.
What soil does Harvestlice need?
The species tolerates light sandy, medium loamy and heavy clay soils, and grows across mildly acidic, neutral and mildly alkaline pH, with a noted preference for calcareous (lime-rich) ground. Field accounts also describe it succeeding on silty wetland soils.
What temperature does Harvestlice tolerate?
Swamp agrimony is extremely cold-hardy, with field reports of survival to about −33°F (roughly −36°C), placing it comfortably within USDA zones around 3 through 9 across its native eastern North American range.
Does Harvestlice have a scent?
The foliage and plant material of Agrimonia parviflora are notably aromatic — birds incorporate it into nests specifically because the scent repels parasites. The precise character of the scent is not described in reviewed sources.
What do Harvestlice flowers look like?
Flowers are tiny, bright yellow and only about a quarter-inch across, each with five petals, five sepals and roughly 5–10 stamens, arranged on long, slender, usually unbranched spikes. They appear from June through August and are hermaphroditic and self-fertile while also attracting bees and flies for nectar.
Can I grow Harvestlice outdoors?
How do I propagate Harvestlice?
Propagate from seed, which germinates in two to six weeks at about 13°C (55°F), or by dividing established clumps in autumn. The hooked burs disperse naturally on mammal fur, bird feathers and clothing, and plants self-sow readily where they are happy.
How is Harvestlice pollinated?
Flowers are hermaphroditic and self-fertile, so plants can set seed without a pollinator, but they also produce nectar that attracts bees and various flies, which contribute to outcrossing.
Is Harvestlice edible?
Plants For A Future rates Agrimonia parviflora 0 of 5 for edibility, and no edible parts are documented; the foliage is noted to have a bitter taste that deters most browsers.
What are the medicinal uses of Harvestlice?
A tea brewed from the whole plant is described as astringent and has been used in folk medicine for diarrhea, minor bleeding, wounds and gallbladder inflammation, with infusions taken for fevers and root preparations used as a tonic. It is generally considered a minor medicinal herb (rated 2 of 5 by Plants For A Future) and shares the broader Agrimonia genus's traditional reputation for treating mild diarrhea and oral inflammation.
Are there other uses for Harvestlice?
No non-food, non-medicinal practical uses are documented for swamp agrimony, which Plants For A Future rates 0 of 5 for other uses.
What pests and diseases affect Harvestlice?
No specific pest or disease problems are documented for Agrimonia parviflora in the reviewed sources. No known hazards are recorded, suggesting it is generally problem-free in appropriate growing conditions.
How do I care for Harvestlice through the seasons?
The plant is a deciduous perennial that flowers in midsummer, ripens seed in late summer to early autumn, and senesces in fall before regrowing from its fibrous root system the following spring. Allowing the burs to mature before cutting back lets it self-sow naturally.
Are there varieties or similar species to Harvestlice?
Agrimonia parviflora is sometimes confused with Agrimonia gryposepala (common agrimony); A. parviflora is recognized by its much higher leaflet count (often 11–23, with smaller interspersed secondary leaflets) and its hairy, spineless stems.
What is the growth pattern and size of Harvestlice?
What is the region of origin of Harvestlice
What are the water needs for Harvestlice
What is the sunlight requirement for Harvestlice
Is Harvestlice toxic to humans/pets?
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