Not exactly a popular tree, Ailanthus altissima (tree-of-heaven, family Simaroubaceae) is a very fast growing weed of roadsides, open woods and edges of woods. It's flowering now. Big whoop.

Caledonia Woods is a 32.8 acre lowland forest owned and managed as a nature preserve by the Marion County Prairie Parks Commission. It is bordered by the Olentangy (Whetstone) River. An active set of RR tracks runs through it. There is a small barren area that was once used as a disposal site for dredge spoils. It is occupied by alien weeds and native early succession pioneer trees. One of the weeds is a delicate member of the pink family (Caryophyllaceae) called "night-flowering catchfly" (Silene noctiflora). It is presently in fruit, not flower. The fruit is a capsule that opens by teeth (suggestive of a moss capsule).


The reason for the odd name is that the stem has sticky parts along its length. In a couple of places about an inch long, it's tacky like flypaper. This seems more likely to be an adaptation to discourage ants rather than flies, since ants are more likey to try and crawl up stems than are flies. Flies fly.



Nearby, field bindweed, Convolvulus arvensis (family Convolvulaceae) is merrily being visited by a syrphid fly. These look like little bees, but they're flies. Flies are easy to recognize if you can get close enough. They have only one pair of wings, the front pair. The hind wing are modified into little knob-like balancing organs called "halteres."

Many central Ohio roads are now flanked by a dense monoculture of our most poisonous poisonous plant, poison hemlock, Conium maculatum. (Danger, poison!)

Conium is a very typical member of the Apiaceae --a biennial with compound leaves that have sheathing bases, and tiny white flowers produced in compound umbels. As such it's fairly similar to another abundant weed, the harmless Queen Anne's lace (Daucus carota), which is also called wild carrot because it actually is wild carrot. Here are some identification tips for the poison hemlock I examined today, with comparison to the friendly Queen Anne's lace.

Poison hemlock is much bigger than Queen Anne's lace, and begins blooming several weeks earlier.





The stem is another useful identification feature. Poison hemlock is glabrous (hairless) and has purple spots on the stem. (The specific epithet --maculatum --means "spotted").

Moreover, the poison hemlock stem is glaucous. Birders might know a powdery-white northern bird called a glaucous gull. "Glaucous" is also a botanical term describing a surface with a white powdery bloom that can be rubbed off with your fingers. Poison hemlock, Conium maculatum demonstrates this property well. Here's a pair of pictures before and after rubbing the stem.

There are several wetland monocots with sword-like leaves that could be mistaken for one another: irises (Iris), bur-reed (Sparganium), cat-tails (Typha) and sweetflag (Acorus). Today I saw two of these growing side-by-side.

Photographing the angelica (below) was especially pleasant because of a sweet fragrance that emanated from sweetflag (Acorus sp., family Acoraceae) crushed underfoot. (The abbreviation "sp." signifies "species" as a singular noun. It is used when one doesn't know the exact species or for some other reason chooses not to give a complete scientific name. The sweetflag problem is there are evidently two species in Ohio, a recently recognized native one called A. americanus and the introduced A. calamus. According to this website they are separated by some picky little leaf veination detail that I didn't know enough to examine while in the field.) Sweetflag is by far the dominant plant here, but there are a few individuals of cat-tail (presumably Typha latifolia, family Typhaceae) scattered here and there.

The plant family Apiaceae is very distinctive. It used to be called the "Umbeliferae" because so many members produce flowers in compound umbels. One that does so particularly dramatically is angelica, Angelicqa atropurpurea, a huge wetland plant the umbels of which are strikingly globe-shaped.