Explore Plants

Share

Ask Mr. Smarty Plants

Ask Mr. Smarty Plants is a free service provided by the staff and volunteers at the Lady Bird Johnson Wildflower Center.

Search Smarty Plants
    
 

Can't find the answer in our existing FAQs, submit a question to Mr. Smarty Plants.
Need help with plant identification, visit the plant identification page.

rate this answer
Not Yet Rated

Tuesday - April 12, 2005

From: Pittsburgh, PA
Region: Mid-Atlantic
Topic: Plant Identification
Title: Differentiating between Spiraea betulifolia and Spiraea japonica
Answered by: Joe Marcus

QUESTION:

How can I tell the difference between Spiraea betulifolia var. corymbosa (an imperiled species) and Spiraea japonica (an invasive species) in the wild? They both seem to be the same size, color, habit, etc.

ANSWER:

There are a couple ways to distinguish Spiraea betulifolia var. corymbosa from Spiraea japonica. Unfortunately, there are also some pitfalls in these distinctions! In general, our native spirea is white-flowering (occasionally lightly blushed pink), while S. japonica is typically pink to rose-red flowered. The exceptions are uncommon, but can make positive identification difficult. The leaves of S. betulifolia var. corymbosa are broadly ovate to oblong or obovate, between 4 and 7 cm long and usually less than twice as long as wide. If you are not familiar with botanical terminology think, "arrowhead shaped". Spiraea japonica leaves are lanceolate or lance-ovate, between 8 and 15 cm long and 2.5 to 5 cm wide, or typically more than twice as long as wide. Think, "spearpoint or lancehead shaped". Further, the toothed edge of Spiraea betulifolia var. corymbosa usually extends only from the leaf tip to 1/2 to 2/3 of the length of the leaf toward the base, while the toothed edge of S. japonica leaves typically extend nearly to their base. Spiraea japonica escapes from cultivation and can often be found growing in the wild. To further complicate matters, the many cultivars of S. japonica can confuse identification.
 

More Plant Identification Questions

Plant identification
September 06, 2009 - Could you please identify a plant with a scalloped elephant ear type leaf, wooden base with oval areas where old large wooden roots from above the ground have fallen off.
view the full question and answer

Identity of a pink-flowering bush with flowers like sweet peas
June 29, 2012 - I have found a pink flowering small tree / bush that has picky branches kind of looks like sweet pea flowers and the leaves kind of look like shumac. Growing near the thick woods of northern MI
view the full question and answer

Mystery Iris-like plant in Tennessee
September 02, 2008 - What is this flower? It came up and bloomed for about five days then died. It was a beautiful white trumpet shaped flower. It had one stem with four flowers. It came up like an Iris but we nver plante...
view the full question and answer

Smarty Plants on Hesperaloe parviflora
August 22, 2005 - On your home website there is an orange flower that is tall and has tall leaves. is it a cactus? Thanks.
view the full question and answer

Identification of wildflowers in Wyoming
July 15, 2007 - I have taken some photos of wildflowers in Wyoming and although I have looked in several books and this website, I am still unable to identify a few. 1) very small white and lt. blue flower with 5 sep...
view the full question and answer

Smarty Plants's Facebook profile Support the Wildflower Center by Donating Online or Becoming a Member today.

Mr. Smarty Plants wants you to be his Facebook friend. Click the Facebook icon to add yourself to Mr. Smarty Plants list of friends.