Blue Stem

20150923-_DSC0030

blue-stem goldenrod, aka wreath goldenrod
Solidago caesia
Asteraceae

 

As I wrote previously (and last year), goldenrod identification can get really tricky. Both zigzag goldenrod and blue-stem goldenrod have unusual characteristics, though. For one thing, they’re woodland plants (most goldenrods like full sun, or at least more sun). And they bloom relatively late. And few other goldenrod species have flower clusters in the leaf axils; most goldenrods have terminal, or at least upper-stem, inflorescences.

20151010-_DSC0048

Whereas zigzag has big, oval, serrated mid-stem leaves, bluestem has linear, smooth-edged or serrated, one-nerved leaves that are sessile, all the way along the stem, which may or may not carry a slight blue tint. Better to rely on leaf shape and the presence of axillary flowers for identification.  As you can see from the photos, it will sometimes have an upright habit, but more often flops over under the weight of the blossoms.

20151010-_DSC0004

 

 

The specific epithet is from the Latin caesius, meaning cutting or piercing.

Blue-stem goldenrod can be found from Texas in the south and northeastward into Quebec.  It’s endangered in Wisconsin.

Bent Stem

20151014-_DSC0054

 

zigzag goldenrod
Solidao flexicaulis
Asteraceae

 

 

 

 

The late summer not-quite drought wiped out a lot of flowers, but others are starting to bloom after the recent rains. The earlier goldenrods are mostly gone, but this is one of two later-blooming species that are coming along nicely.

With over 70 species in the continental US (two dozen of which occur in the mid-Atlantic Piedmont), it can be difficult to distinguish one Solidago from another. This species is an easy one, though, with large, serrated, ovate leaves with petioles at the middle of the (usually) unbranched stem, and upper stem leaves that are lanceolate. In most specimens, there’s a bend at each node, hence the name “zigzag” goldenrod.  (The specific epithet, flexicaulis, means bent stem.)

20151014-_DSC0064

 

zigzag goldenrod typically has only a few ray flowers; in this photo you can see the opened disk flowers

 

 

 

 

 

Zigzag goldenrod is found east of the Rockies except in parts of the deep South. It’s threatened in Rhode Island.

20151014-_DSC0049

 

and in this photo, the disk flowers have not yet opened