As my 3-year-old grandson, Miles, always notes: “Grandpa, you love trees.” It is so; he has me with the word “trees.”  Since we are in Brooklyn now, awaiting grandson No. 2, I have enjoyed looking at the structure of some New York City street trees: from London planetrees to Chinese scholar trees, from sweetgums and their mace-like prickly fruits to Kentucky coffeetrees. Looking downward, there are pools of planetree seeds and fallen fruits along the curbs in the streets. And, behold, in the under-tree world, the snowdrops are out: harbingers of spring! 

I gave a talk two weeks ago to the Ohio Chapter of the International Society of Arboriculture at its convention in Cleveland on oak wilt disease, a serious fungal disease of the water-conductive system of the plant, especially of oak species in the red oak group. I have written of it and will do more in coming months, but for now, let us take a quick look at oaks. They are in the genus Quercus, and in the Fagaceae family along with beeches and chestnuts. There are over 600 oak species worldwide, all native to the Northern Hemisphere, of which 90 species are native to the United States.    

Here is something you can teach your children and your children can teach you: Oak-lovers divide oaks into the red oak group and the white oak group. What is the difference?   

First and foremost, all of the oak species in the red oak group, such as red, scarlet and pin, sometimes interbreed; but not with oaks in the white oak group, such as white, bur and chestnut oaks that interbreed only with other oaks in the white oak group. This is partly due to the fact that the red oak group species take two years for an acorn (the oak fruit) to mature, while oaks in the white oak group develop acorns in a single year.  Animals that eat acorns have learned this, since this maturity difference affects levels of tannins and other chemicals, which matters relative to long-term vs. short-term energy and storage differences for the different acorns.   

So, how do we tell the difference? Oaks in the red oak group have bristle tips at the lobes of the leaves; those in the white oak group do not. I used to think it was pointed lobes (red) vs. rounded lobes (white), but that does not account for oaks like the shingle oak or the willow oak that really do not have lobes, though the tip of the elongate leaf blade looks rounded. However, there is a bristle tip on the end of the long leaf, so they are in the red oak group.  

Which brings us to one last difference: The red oak group has a vascular system (water and nutrient conduction from roots to leaves) that transports water and minerals quickly throughout the plant, while the white oak group has invaginations called tyloses that slow the movement. This turns out to be important with — back to the beginning — oak wilt. The fungus plugs up this system and kills the red oak group of species faster and more reliably than it does the white oak group of oaks. Plant anatomy matters! 

Oh, one more difference, useful in winter tree ID: Oaks have clustered terminal buds.  

In the last Almanac I mentioned the books “Urban Lichens” by Jessica L. Allen and James C. Lendemer and the classic “Lichens of North America,” a glorious almost 800-page tome with eye-popping pictures of these fascinating multi-kingdom symbiotic organisms. Since the softcover handbook-size “Urban Lichens” is only 158 pages long, I shall share something from it this time, about lichen dyes. As noted in “Urban Lichens,” they “come in a full rainbow of colors, from red, orange, and yellow and green, to blue, and every shade of brown and gray in between.” And their chemistry has resulted in development of natural dyes for millennia, with periods of widespread use such as in Scotland early in the industrial revolution.   

Here is a serial look at Secrest Arboretum curator Jason Veil’s “Proven Performers of Secrest Arboretum”: This time let’s look at a maple unveiled. It is Acer miyabei, the miyabe maple, a species endangered now in its limited range along streams in Hokkaido, Japan. Horticultural versions — propagated asexually after mutations/genetic recombination — include the trademarked Rugged Ridge with corky bark offered by J. Frank Schmidt Nursery in Oregon; and State Street, a selection from Chicago’s Morton Arboretum. Both are highly adaptable, hardy, oval-shaped and mostly upright and with dark green, waxy leaves reminiscent of hedge maple. I shall plant one or two this spring.  

I have always enjoyed Greek and Roman mythology, especially with respect to plants referenced in the myths, and on Valentine’s Day dipped into Edith Hamilton’s classic “Mythology” text and the chapter “Eight Tales of Lovers.” I had not known of the tale of Pyramus & Thisbe, an early Romeo & Juliet-esque tale. They were forbidden to meet, but planned a tryst at the Tomb of Ninus at the mulberry tree with its snow-white fruits.  

Thisbe arrives first, espies no Paramus, drops her cloak, and departs. A lioness passes by, having fed earlier, and Thisbe’s lost cloak becomes blood-soaked. Paramus arrives, mistakes the scene of the bloody cloak for tragedy, and in despair … You can imagine the rest. Thisbe then returns to find the dead Paramus and follows her lover’s demise. In the myth, the lovers’ deaths become enshrined into now transformed blood-red mulberry fruits. 

The story of these mulberry-crossed lovers gives new depth to my once-mundane mulberry referents. Mulberries (Morus) are often volunteers in gardens, maligned for their coarse, weedy appearance, rapid growth, and messy (yet sugary) fruits, but “never was there such a tale of woe,” than this-be and her paramour.  

Note: Contrary to the mythic origins, there is a native white mulberry species (Morus rubra) and an Asian white mulberry species (Morus alba), and many others types. In the Moraceae family are many important plants including figs, osage-orange (hedge-apple), breadfruit, and jackfruit.   

Next time let's take a deeper look at the fishermen-beloved earthworms, especially the “jumping worm” Asian species, which are now causing ecological disruptions in forested areas. Even the common night crawler, the European earthworm, is not native, but these more recent additions — in the words of Annise Dobson of the University of Connecticut in Julia Rosen’s “Cancel Earthworm” essay — are something else: "If you were to think about the soil food web as the African savanna, it’s like taking out all the animals and just putting in elephants — a ton of elephants.” The flows and throes of Nature.  

Jim Chatfield is a horticulture educator and professor emeritus at Ohio State University Extension. If you have questions about caring for your garden, write to chatfield.1@osu.edu or call 330-466-0270. Please include your phone number if you write.