Characteristics for Identifying Trees – Catkins

Well, today is the first day of spring. We’re expecting another inch or so of snow tonight. Will it ever end? Well, when it does, the first signs of spring may not be leaves emerging from trees, but the flowers of wind pollinated trees. At Dennis Panu Arborist, we use many tree characteristics to identify trees, but, botanically speaking, the most accurate way to identify trees to species is through their flowers. In the spring, several plant families in New England produce their flowers in structures called catkins: small clusters of tiny flowers bearing a resemblance to a cat’s tail. (“Catkin” comes from an old Dutch word for “kitten.”)

Most people think of flowers as being colorful and showy. While this is true when flowers need to attract pollinators like birds or insects, trees with catkins are typically wind-pollinated. Each catkin is made up of many tiny inconspicuous flowers. Most catkins contain male flowers, producing prodigious amounts of pollen, but some trees also have female catkins. In order to facilitate pollen distribution, catkins often appear early in the spring before the tree produces leaves which would block the wind.

If you live in Massachusetts or Connecticut, keep an eye out for trees from these families as they produce flowers in the spring:

• Birch family (Betulaceae)
Trees in this family include birch, hazelnut and hornbeam. Look for the pendulous male catkins dangling in the wind early in the spring. Birch family trees also have their female flowers in catkins, which are much smaller then the male catkins and fixed on the branch. (An exception is hazelnut; the female flowers occur singly on the branch to accommodate the large nuts.) Betulaceae trees are monoecious (“one house”), meaning that male and female flowers occur on the same tree. The species of birch can often be determined by the number of catkins in each cluster. Here are some photos of birch catkins.

• Willow family (Salicaceae)
Including willow, cottonwood and poplar, trees in this family are dioecious (“two houses”), meaning that male and female catkins appear on separate trees. It can be difficult to tell the tiny male and female flowers apart, but an arborist can make the distinction. The fuzzy “pussy willow” you see in flower arrangements is a classic example of this family’s catkins. Also, the drifts of snowy seed pods floating through the air in spring are a sure sign that a female Salicaceae tree is nearby.

• Oak and beech family (Fagaceae)
Everyone recognizes the acorns produced by oaks (or, less commonly, beech nuts), but keep an eye out for these trees’ flowers. Oaks and beeches produce hanging male catkins for wind pollination. Female flowers are not in catkins, however, but occur singly or in pairs in the leaf axils (where the leaf meets the main branch). Fagaceae trees are monoecious, with both male and female flowers on the same tree.

For help identifying trees on your Massachusetts or Connecticut property, or for other tree care service questions, contact Dennis Panu Arborist today.

Why Don’t Trees Freeze?

Last night was the coldest night we have had here in Connecticut in about 20 years; it got down to 8 degrees below zero Farenheit.  That reminded me of a question often asked of me:  Why doesn’t the water in the trees freeze and cause them to burst open like frozen pipes?

Water is stored in trees in two ways; as free water and water stored molecularly.  Free water in the xylem vessels and tracheids that would freeze and burst those cells is purged from the tree.  The remaining water in the tree is stored as individual or small groups of molecules bound to other molecules in the trees’ cells.  Stored that way, the water molecules cannot arrange themselves into the expanding crystal lattice that causes pipes to burst.

ASCA Conference

Last week the American Society of Consulting Arborists (ASCA) held its annual conference at Incline Village, NV on the shore of beautiful Lake Tahoe. The ASCA staff has a knack for choosing some of the most beautiful locations in the country to hold our conferences, so as usual, we spent a few extra days to take in the sights.  Coming from the east coast, I’m always awed by the trees our western members get to work on every day.


This six-foot diameter Incense Cedar is a good example!

ASCA Conferences are known throughout the tree care industry for their exceptional educational programing, and this year was no exception.  Dr. George Hudler from Cornell University gave an excellent presentation on Phytophthora disease on beech trees.  Attorney Hailey Hibler conducted a mock deposition to help train ASCA members in their roles as expert witnesses.  Scott Steen discussed how enhancing our urban forests can save energy.  For example, the city of Sacramento, CA determined that it could reduce the heat island effect by 3 degrees Fahrenheit by doubling its urban forest canopy, a goal that includes planting two million trees.  So far, they have planted 450,000 trees and reduced energy consumption by two million kilowatt hours per year!

I can’t cover the entire program in this post, but rest assured that it was as exciting and informative as could be.

Next year’s conference will be held in San Diego.  I can’t wait!

Paradise Found

A few years back, I had the opportunity to go to Kauai, Hawaii.  I have always been fascinated by Hawaii; in the fifth grade I did a report on Hawaii, writing to the Chamber of Commerce and tourism agencies to gather as much information as I could about the state.  There was no internet in those days, but I got an enthusiastic response from the folks promoting the state’s virtues.

When I finally got there 45 years later, I was not disappointed!  Something was in bloom everywhere!  We were staying in a cottage at Waimea Plantation, surrounded by pomegranate, banana, and star fruit trees.  Fifty foot tall Plumeria trees perfumed the air with their pinwheel shaped white flowers.

A short walk from the cottage brought me to a secluded beach where I could bathe bare to the world.  “Swimming” entailed standing shin deep in in the lukewarm Pacific water while 8 foot waves broke over my head.  All was good.

One night, while laying on the beach, looking at a Milkyway that I had never seen before, I schemed how to get my dog to Kuai so that I would not have to go back to Connecticut.  But, alas, the vacation ended.

It was mid October when the last leg of our return flights landed in Providence.  The landscape was ablaze in fall color.  I was overwhelmed!  For all of the exotic flowers and fruits on the Islands, there is nothing like this in Hawaii!

Arbor Day Celebrations

Its been a busy few weeks and I have been away from the keyboard, but I have some great accomplishments to report.

Arborists throughout the country celebrated Arbor Day on April 29 this year.  A common way that we arborists celebrate is by getting together and donating work at non-profit public or historic sites. This year I had the privilege of participating in two Arbor Day work projects!

The Massachusetts Arborists Association has been sponsoring Arbor Day work days for the past 30 years at many sites including the Boston Common, Pilgrim Memorial Park in Plymouth, MA, Castle Hill in Essex, MA and most recently Minuteman National Park in Concord, MA.  Swarms of member tree companies’ equipment converged to spend the day donating much needed tree work.  Last year we initiated a new twist on the Arbor Day celebration to spread the work and the message of the need to care for our community’s trees to a broader swath of the public.  This new program, dubbed Arbor Day of Service, provided tree care in 34 Massachusetts communities this year!  Continuing our work from last year, I teamed up with Sturbridge Tree Warden and Massachusetts Tree Wardens and Foresters Association member Tom Chamberland to provide tree care at Tantasqua Regional High School.  This is a great venue because groups of students were allowed not only to watch our activities, but to participate.  Students learned about proper planting, pruning, and mulching and got their hands dirty edging and spreading mulch around the trees we pruned.

On the following day I worked on a day of service at the Palmer Arboretum in Woodstock, CT.   This event, organized by Chad Hart of Hart’s Tree Service, Woodstock CT, included Chad’s crew,  myself, and crews from Lindon Tree Service, Eastford, CT and Roy’s Tree Service, Woodstock, CT as well as a group of students from the Hyde School.  Crews of climbers pruned the larger trees and removed some damaged trees, as well as some non-native invasive tree species, while I treated a 30-inch diameter hemlock that was infested with elongate hemlock scale and provided structural pruning to some young ornamental trees.  The arboretum supplied lunch and commemorative tee-shirts for all involved.  It was a fun day to get together with fellow arborists to share ideas and do a good deed for a worthy cause.  I can’t wait  to do it all again next year!

Tom Chamberland instructs a group of students on proper tree care.

Tom Chamberland instructs a group of students on proper tree care.


If you are interested in nominating a site in Massachusetts for an Arbor Day of Service project visit this site:  If you don’t live in Massachusetts but like the idea a day of service, become active by contacting arborists in your area and plan a project of your own!