En EspaŅol
Share

Ask Mr. Smarty Plants

Mr. Smarty Plants - Is western soapberry (Sapindus saponaria var. drummondii) dioecious?

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

Search Smarty Plants
    
 
See a list of all Smarty Plants questions
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

Friday - February 15, 2008

From: Vienna, Austria
Region: Other
Topic: Trees
Title: Is western soapberry (Sapindus saponaria var. drummondii) dioecious?
Answered by: Nan Hampton

QUESTION:

Hi! I found different information on the flowering habits of the western soapberry, Sapindus saponaria var. drummondii. Is it dioecious or polygamo-dioecious or none of them? I have some little seedlings growing, planning to use the fruits for soap in the future. so the flowering habits are important to know for me. How old must the western soapberry be to start flowering? Thanks!

ANSWER:

The mating system of Sapindus saponaria var. drummondii (western soapberry) is, indeed, confusing. Here are what the following sources say about it:

1. In "Manual of the Vascular Plants of Texas" Correll and Johnston say about the Family Sapindaceae: "...staminate and pistillate flowers on separate plants or often some flowers appearing perfect;..." They give no specific description for Sapindus saponaria var. drummondii.

2. In "Trees and Shrubs of the Trans-Pecos and Adjacent Areas" Powell says about the Family Sapindaceae: "Flowers small, unisexual, male and female on separate plants, or flowers perfect, borne in clusters,..."  Again, there is no specific description for Sapindus saponaria var. drummondii.

3. In "Field Guide to Texas Trees" Benny Simpson says about S. saponaria var. drummondii: "Male and female flowers occur on separate trees, and in the deep sands of the Rolling Plains, groves of one to ten acres can be found that are apparently of only one sex. One or several trees spread vegetatively by rhizomes, creating these large groves. The clusters of white flowers produced in May or June must be inspected closely to tell whether the tree is male or female."

4. Information from the U.S. Forest Service says that S. saponaria var. drummondii is dioecious.

5. Finally, in "Forest Trees of Oklahoma: How to Know Them" Little says about Sapindus drummondii (syn.= S. saponaria var. drummondii): "Flowers many, almost stalkless, mostly male and female...."

So, I think you can probably expect your trees to be dioecious with either staminate (male) or pistillate (female) flowers, but don't be surprised if there are a few perfect (with both male and female parts) flowers scattered about on some of the trees.

Now, how long it will be until they bloom? This is another question we can't answer precisely. The U.S. Forest Service describes S. saponaria var. drummondii as being moderately slow growing and the Texas Forest Service Texas Tree Planting Guide describes its growth rate as moderate.

Here are a couple of quotes from the "Manual of Woody Landscape Plants" by Michael Dirr describing growth rate of trees:

"Rate of growth refers to the vertical increase in growth unless specified differently. Rate, as is true for size, is influenced by numerous variables such as soil, drainage, water, fertility, light, exposure, ad infinitum."

"The designation slow means the plant grows 12" or less per year; medium refers to 13 to 24" of growth; and fast to 25" or greater."

This, of course, doesn't answer when they might bloom. That, too, will depend on a number factors similar to those associated with growth. I would think, however, that it would be 4 to 5 years before they are as tall as 5 or 6 feet. They might possibly bloom by then. This is a lot of arm-waving, I know, but I'm afraid that's about the best I can do for you.


Sapindus saponaria var. drummondii

Sapindus saponaria var. drummondii

Sapindus saponaria var. drummondii

Sapindus saponaria var. drummondii

 

 

More Trees Questions

Sprouts from Live Oak in Austin
April 06, 2011 - I have an Escarpment Live Oak..quercus fusiformis.? I get tired of all the sprouts that come up around this tree..My yard person wants to pull them up or get a roto tiller after them..? I had been t...
view the full question and answer

Transplanting a blue spruce from Pingee Grove IL
August 30, 2012 - Transplant 18" Blue spruce from 5 gal. bucket to ground.
view the full question and answer

Apples, pears and geraniums in Kipling, Saskatchewan
March 30, 2013 - My geranium's leaves became yellow - Why? Where can I buy a good nice apple tree? Will apples and pears grow in south Saskatchewan?
view the full question and answer

Need a tree to grow in the middle of a retention pond in Pennsylvania
June 03, 2010 - I have a shallow retention pond in my yard in South Eastern Pennsylvania. The pond is used for rainwater runoff and also for natural springs that are located below the surface. If I plant a tree in th...
view the full question and answer

Dying branches on Texas Mountain Laurel from Kempner TX
September 14, 2012 - The branches on my Texas Mountain Laurel are very dry and brittle. The leaves are also starting to die. The tree has been in my yard for six years and prior to that it sat wrapped in burlap for ov...
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.
E-NEWSLETTER | BECOME A MEMBER | DONATE NOW | MEDIA | SITEMAP
© 2014 Lady Bird Johnson Wildflower Center