Variations on a Theme: Vervains


blue vervain
Verbena hastata





white vervain
Verbena urticifolia


As you can see from the pictures, these two closely related plants have similar inflorescences.  Both species can grow as much as 5 or 6 feet tall.  Authorities vary on this; I’ve seen white vervain at 5 feet and blue vervain at 4 feet.

20150728-20150728-DSC_0211Blue vervain is a plant of wet places (another common name for it is swamp vervain), and is found in every state of the US except Alaska and Hawaii, and almost every province of Canada.  It’s considered weedy by some authorities.



Its leaves are long and narrow…






…while the leaves of white vervain are more oval.






You’ll find white vervain in drier situations, usually in more shade; this small specimen was right along the Billy Goat C trail.  It was almost done blooming, so you can’t quite see the diminutive flowers*.

White vervain isn’t as widespread as blue; it can be found from the Great Plains eastward, but not in the West.  Kentucky considers it possibly weedy, while Maine considers it possibly extirpated.


There are almost 40 native species of Verbena in the US, with widely varying distribution, and about 8 alien species.  Of the native species, 7 occur in the mid-Atlantic Piedmont.  One of these, Verbena x engelmannii, appears to be a naturally-occurring cross between V. hastata and V. urticifolia.  It’s described as having bluish-purple flowers with egg-shaped leaves**.

20150730-20150730-_DSC0263(sorry, this is not V. x engelmannii, it’s V. hastata again)

*or as the Illinois Wildflowers site says, “The lanky branches of the inflorescence are rather long, however, and they sprawl in different directions. This makes the inflorescence difficult to photograph in its entirety.”

**Morton Arboretum via

Flowers of the Day: Blue Vervain, White Vervain

Verbena hastata and Verbena urticifolia; Verbenaceae (verbena family)



Blue vervain, also known as swamp vervain, likes wet soils and full sun, and can be found all across the US in two varieties.  Some authorities consider it weedy in the West.  It grows up to five feet tall, with flower spikes up to half a foot long; the individual flowers are about 1/4″ across.

White vervain grows somewhat larger (up to six feet), with longer flower spikes (up to two feet), but much smaller flowers (1/8″ across).  It prefers slightly drier soils and more shade, though I have seen it growing mere feet away from blue vervain.  There are two varieties of white vervain, too, but neither is found in the West.  Some authorities consider it potentially weedy or invasive.  It is listed as possibly extirpated in Maine.


Flower of the Day: Southern Agrimony

aka harvestlice, aka swamp agrimony (Agrimonia parviflora); Rosaceae (rose family)


I know, I know, you were expecting a picture of a flower.  This species of agrimony has small yellow flowers, about 1/4″ wide at most, that are very typical of the rose family. It’s another example of medium-sized plants with long, spiky inflorescences and itty bitty flowers (like vervain, jumpseed, lopseed).

I like this plant for the sound of the name, which comes from the Greek for “poppy”. But really, it’s about the leaf.  Is that not a fascinating leaf?  Shown above is a single, pinnately compound leaf, with 17 primary leaflets and about 30 secondary leaflets.  Nevermind about the flowers, I just love the plant:

20140807-DSC_0090  Okay, here are some flower pics:

20140806-DSC_0126This one is actually a different species: common agrimony (A. gryposepala).  Leaf is not nearly as nifty: 20140721-DSC_0484 Southern agrimony flowers are similar to common agrimony flowers: