Agrimonia striata (Roadside Agrimony)
|Also known as:||Woodland Agrimony, Woodland Grooveburr|
|Habitat:||part shade, sun; average moisture; open woods, thickets, woodland edges, shores, banks, swamps|
|Bloom season:||June - September|
|Plant height:||2 to 6 feet|
|Wetland Indicator Status:||GP: FACU MW: FACU NCNE: FACU|
|MN county distribution (click map to enlarge):|
|National distribution (click map to enlarge):|
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Elongating spike-like racemes at the top of the stem and arising from upper leaf axils. Flowers are ¼ to about 1/3 inch across with 5 oval yellow petals and 5 to 10 yellow stamens, the tips yellow to orange to red. Alternating with the petals are 5 green sepals that are pointed at the tip, sparsely hairy and shorter than the petals.
Surrounding the base is a calyx-like structure known as a hypanthium, narrowed to a stalk-like base, with 3 or 4 rows of hooked, green to purplish bristles in a ring around the tip and a leaf-like bract at the base. Flowers are ascending to spreading at flowering time, alternate to opposite (or nearly so), may be widely spaced on the lower part of the cluster and more compact above. Stalks, sepals, bracts and the hypanthium are all sparsely gland-dotted and variously covered in white hairs.
Leaves and stems:
Leaves are compound with 3 to 11 major leaflets (5 to 7 on mid-stem), and 1 to 4 pairs of small leaflets in between the larger ones. The end leaflet is largest, 1½ to 4¼ inches long, ¾ to 1½ inches wide, becoming smaller towards the base of the compound leaf. Leaflets are generally lance-elliptic to somewhat diamond shaped, mostly widest near the middle, coarsely toothed with pointed to somewhat rounded teeth.
At the base of the leaf stalk is a pair of leafy appendages (stipules), those on mid-stem each lance to ½ egg-shaped in outline, up to about ¾ inch long, about half as wide, usually toothless on the upper half, the lower half toothless to coarsely toothed around the edge. The upper surface of leaflets and stipules is hairless to sparsely hairy, the lower moderately gland-dotted and densely hairy along the veins, with hairs mostly appressed.
The hypanthium becomes nodding and enlarges to about ¼ inch long at maturity, the base usually cone to bell-shaped, with 10 deep grooves. The surface is sparsely covered in long hairs, especially near the base and in the grooves, mixed with minute glandular hairs. The sepals persist and become erect, forming a beak at the tip, usually a bit longer than the bristles. The rows of hooked bristles spread out, the top row becoming erect and the lowest row spreading at a 90° angle or nearly so. Bristles may all become erect when dry. Inside the hypanthium is a single seed.
There are 3 Agrimony species in Minnesota, all of which have similar leaves, flowers and fruit. Roadside Agrimony most closely resembles Downy Agrimony (Agrimonia pubescens), which has similar stem hairs but the leaf underside has few glands, the leaf hairs are spreading, not appressed, stipules tend to be toothed all along the outer edge, roots are tuberous, and it is mostly found within the southeast quadrant where Roadside Agrimony has fibrous roots and ranges farther north and west in the state. The third Agrimonia species, Tall Hairy Agrimony (Agrimonia gryposepala), is probably the easiest to recognize from the dense covering of short, glandular hairs mixed with sparse long, spreading non-glandular hairs on both stems and leaf undersides. While many references note differences in the hypanthium shape of the 3 species, this is often a really subtle distinction so we tend to ignore it, though A. pubescens seems to be the smallest of the 3. Some references also note that A. pubescens flowers are mostly alternate where A. striata are mostly nearly opposite, but we haven't found this a reliable distinction in the field either; however, it is also noted that alternate flowers (A. pubescens) are more likely to be well separated where opposite flowers (A. striata) are more likely to be crowded. That may or may not be useful to a positive ID.
The MN distribution maps for A. striata and A. gryposepala should be taken with a grain of salt. For A. gryposepala, the DNR's MNTaxa distribution does not include more than half the counties which have herbarium records. Coincidentally(?), they list a number of these same counties for A. striata, but there are no corresponding herbarium records. We can't know for certain what's what without reviewing the actual specimens, but some are likely mis-IDs. So look for the glandular hairs on the stems to separate these two.
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- Roadside Agrimony plants
- Roadside Agrimony plants
- garden-grown Roadside Agrimony
- comparison of Agrimonia pubescens and A. striata glands and hairs on leaf underside
- purplish bristles
- close-up of fruit
- more flowers
- comparison of MN Agrimonia species stem hairs
- comparison of MN Agrimonia species stipules
Photos by K. Chayka taken in Cook, Lake, Ottertail, Pope and Ramsey counties. Photos courtesy Peter M. Dziuk taken in Cook, Pope, Ramsey, St. Louis and Wabasha counties.
Have you seen this plant in Minnesota, or have any other comments about it?