HEBERLING LAB

Spring at Powdermill.
An early bloomer.
 
This specimen of coltsfoot (Tussilago farfara) was collected at Powdermill Nature Reserve, the field station of Carnegie Museum of Natural History in 1957, just one year after Powdermill was established. It was collected by Leroy Henry, a curator of botany at the museum from 1937 until 1972 (though was also affiliated with museum before and after that, too!).  Henry is an important collector for our region, with >36,000 specimens in the Carnegie Museum herbarium.
 
At first look, the plant may be confused with your common dandelion.  It has definite similarities, as it is in the same plant family, Asteraceae, and with yellow flowers.  But, as you’ll notice from the specimen – it doesn’t have leaves!
 
Coltsfoot is introduced to Pennsylvania, native to Europe, and quite unique in our flora.  It blooms very early in the spring, with dandelion-like flowers poking through.  The leaves will soon follow, shaped like – well – a colt’s foot!  Quite different than dandelion. 
 
Its blooming also makes it a great species to track changes in bloom time using herbarium specimens.  The species was among the first to be use in a pioneering study published in 2006 using herbarium specimens by Claud Lavoie and Daniel Lachance.  In Southern Quebec, they found coltsfoot bloomed 15-31 days earlier in recent decades, compared to pre-1950. Earlier blooming was strongly linked to climate change in the region.  The plants also showed a clear signal of flowering earlier in the city (due to urban heat island).
 
We have plenty of spring ephemerals that bloom early, but coltsfoot doesn’t die off by summer.  The plant will keep its leaves well after it blooms, into late fall.
 
This strategy is interesting, and I can’t think of many of plants in our flora that does this.  Is it on to something?
 
Keep an eye out for coltsfoot, especially along wooded roadsides.  Once you see a big bloom, check back later in the year.  The leaves can get quite large.
 
Find this specimen and more here: https://midatlanticherbaria.org/portal/collections/list.php?db=all&catnum=CM092465&includeothercatnum=1
 

Spring is springing as we speak
in the city and beyond.
 
This specimen of common chickweed (Stellaria media) was collected on the campus of Carnegie Mellon University in Pittsburgh in a “mostly shady area.”  Though small, if you look closely you are met with a charismatic tiny flower.  Common chickweed is incredibly common across the world, found in every continent (except perhaps Antarctica?).  Like many cosmopolitan lawn weeds, it is native to “Eurasia” and its exact native range is unclear.  But it is considered not native to North America.
 
Common chickweed can be found from an urban lawn to a forest in Pennsylvania.  The plants can form a mat along the ground.  They can be found just about year round when snow isn’t on the ground, and like dandelion, flowers throughout the year.
 
But the flowers now are also telling – spring is on the way.  For some plants, such as skunk cabbage and red maple, spring has already sprung.
 
This species is a good one to look out for during the upcoming City Nature Challenge!
 
Find this specimen and more here: https://midatlanticherbaria.org/portal/collections/list.php?db=all&catnum=CM540683&includeothercatnum=1