Not all yellow flowers are cheery

I promised information about Ranunculus ficaria (lesser celandine) since I saw my first clump of Ranunculus threatening to bloom last week. I also discovered quite a few more plants while hiking this weekend.   I will spend some time pulling out some of the invasives along a trail as I am hiking.  It is very important to leave no trace when you hike and take only pictures but, I can't resist some of the very invasive plants such as celandine, garlic mustard, and small euyonomus trees.  Please, if you are going to do a "good" deed such as invasive removal on a property that you are hiking YOU MUST BE VERY CONFIDENT OF WHAT YOU ARE REMOVING, AND RECOGNIZE WHETHER THE PROPERTY OWNERS/MANAGERS ARE LIKELY TO PRACTICE INVASIVE CONTROL. SOME OF OUR NATIVE PLANTS CAN BE MISIDENTIFIED AS AN INVASIVE SO MAKE SURE YOU KNOW WHAT YOU ARE TARGETING!

If you are not sure what the plant is, you may recognize the photograph of the yellow carpet.  This scene is repeated many times throughout the Brandywine in the spring.  It is a small low growing plant with a very impressive underground network of bulbets and tubers that can continue to flourish if separated from the main plant.  The flower is typically bright yellow and the leaves are a deep green. 

The leaf of celandine, which is the only part of the plant that is currently showing, looks VERY similar to the leaf of a violet.  Note in the photograph the violet is on the left and the celandine is on the right.  Violet's tend to have more rounded lobes, and the celandine is sharper with points.  Typically the celandine has a glossier look than the violet.  You should be sure that you can differentiate between the two before you pull out leaves that belong to violets.   Once they bloom, they are easier to differentiate, but not all violets are purple or white, there are yellow violets native to our area.  Also, once the blooming has begun, it is typically more difficult to remove all of the tubers from the ground.

 When you pull out the celandine be sure to remove all of the tubers and bulbets that are attached to the plant.   You can actually assist in the spreading of the plant by leaving them behind.  I will lay the plant on a rock where it has little chance of re-sprouting in the ground.  You can also control celandine by spraying a glyphosate based herbicide at a low concentration.   Glyphosate is non-selective so it should be used with care since you may harm some of the spring ephemerals in the process.  If the area is very sensitive, I would recommend individually painting each celandine leaf.  This may be time consuming, but it is a great way to be very selective and to inhibit any further spread. Typically manual control is recommended for very small infestations and you will have to resort to chemical to obtain complete control when you are dealing with the "blanket" effect as in the earlier photograph.