There are a number of trees in my neighborhood which seem to be abnormal. The branches are changing shape, and instead of being round, they have ridges growing lengthwise along them. It makes the branches look misshapen, almost like elongated stars. It looks unnatural, maybe like a disease. I think the trees are maples. Do you know what could be causing this?
There are some trees and shrubs whose branches normally take the form I think you are describing, which is sometimes referred to as winged or alate. I am not aware of maples which do this, so I wonder if perhaps you were seeing sweet gum trees, or Liquidambar styraciflua. According to information from the Mathilda Mathias Botanical Garden in Los Angeles,
“One diagnostic character is the presence of corky wings on young stems. In some cases, wings are due to stimulation of localized phellogens along a stem angle, as in winged euonymus (Euonymus alatus). Wings also occur on young stems of sweet gum (Liquidambar). Longitudinal splitting is the cause of stem wings in certain species of elm (Ulmus.)
Here are more images:
Euonymus alatus
Ulmus alata
Liquidambar styraciflua
According to the book Plant Form: an Illustrated Guide to Flowering Plant Morphology by Adrian Bell (Oxford University Press, 1990), these wings can be part of the way a particular plant grows. The book shows an illustration of metamers (also called phytomers), which are repeated constructional units
(like building blocks) in the plant’s development. From my unscientific perspective, I wondered if the wings might have a leaflike photosynthetic function. I did find an article from the Botanical Gazette from February 1889 (yes, 19th century!) by Emily Gregory which examines this issue. It seems to suggest that the corky wings on the branches may have the function of increasing branch circumference and this may provide the tree with extra protection.
A version of this question and answer appeared in the Spring 2014 issue of the Washington Park Arboretum Bulletin.
How on earth did Liquidambar enter the otherwise Latin list of genera? I have asked a lot of gardening experts, and no one else seems bothered by this. Can you assuage my anguish?
There are quite a few botanical (scientific) names that are not Latin in origin–many are Greek, or modeled after the name of the plant explorer who ‘discovered’ them, or the plant’s geographical origins, to name a few possibilities.
Liquidambar actually does have Latin roots. According to Geoffrey Grigson’s A Dictionary of English Plant Names (Allen Lane, 1974), Liquidambar styraciflua, a native of North America and Mexico, was introduced in 1683. The name refers to the tree’s fragrant gum or resin:
liquidambar (liquidus, ‘liquid,’ + medieval Latin ambra, ‘amber’)
A Spanish physician, Francisco Hernandez, coined the name in the 16th century. “The gum was sold in apothecaries’ shops as Balsamum liquidambrae.” The species name, styraciflua, is derived from a Latin phrase meaning ‘storax fluid.’ From the following article in the Bulletin of Hispanic Studies, Volume 86, I discovered more information about storax:
“According to Dioscorides:
storax is the sap of a tree which resembles the quince tree. The best is yellow, fatty and resinous; it has whitish lumps, its scent lasts for a very long time and when softened, it releases some honey-like moisture.“
Don’t despair if verticillium wilt lives in your garden’s soil because there are many resistant plants. A few verticillium-resistant trees include Apple and Crabapple, Mountain Ash, Ginkgo, Sweet Gum, Katsura, Douglas Fir, Arborvitae and White Oak. A long list of susceptible and resistant trees, shrubs, perennials and vegetables.
There is some evidence that broccoli (chopped up new shoots worked into the soil) can act as a soil fumigant, if added to the soil before planting. Studies were done by Krishna Subbarao at University of California, Davis, and showed reduced incidence of wilt in cauliflower crops where broccoli had been planted and its residue added to the soil.