Tree of Heaven Flowers.
OSU at Marion
June 12, 2008
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.
tree of heaven flowering
Tree-of-heaven (Ailanthis altissima), June 12, 2008, OSU at Marion.
The breeding system of this plant is described as “polygamous” defined as bearing partly perfect, and partly unisexual flowers. Last year as part of the “tree flowers” project, I tried to photograph this species at a location in Columbus where, as luck would have it, all the trees were staminate (male)! This time and place, however, the plants are more cooperative, bearing what looks like perfect (bisexual) flowers. Here’s a closeup.
Ailanthus altissima flower, June 12, 2008, Marion County, OH.
But how on earth will flowers like these –having a deeply 5-parted ovary –develop into fruits like the ones shown below (taken at the same locality late least year). Tree-of-heaven produces winged one-seeded fruits, called samaras, as do ash, maple, elm, and tulip-tree. It doesn’t seem possible. We’ll have to wait and see!
Alanthus (tree-of-heaven) fruits, OSU at Marion, October 17, 2007.
Catchfly, and an Uncaught Fly
Caledonia, Marion County, OH.
June 12, 2008
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).
Night-flowering catchfly (Silene noctiflora) fruits, Caledonia, OH, June 12, 2008.
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.
Night-flowering catchfly (Silene noctiflora) stem, June 12, 2008, Caledonia, Ohio.
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.”
Field bindweed (Convolvulus arvensis) being visited by a syrphid fly.
Caledonia, Marion County, OH, June 12, 2008.
Does the syrphid fly pollinate the bindweed? It isn’t apparent from this observation. The fly certainly grabbed on to the pollen-receptive stigma, as shown in this “actual pixels” blow-up from the photo above. But there doesn’t seem to be any pollen accumulated on the fly’s body that could transfer to the stigmas.
fly on styles of bindween
Syrphid fly grasping stigmas of bindweed, Caledonia, Marion County, OH, June 12, 2008.
It’s also hard to see exactly what the fly is getting from the flower. Some flies, including houseflies and apparently this one, have “sponging-sucking” mouthparts, shown below in an enlargement of another picture. We can see it is trained on the pollen-bearing anther. Does this fly ingest pollen? It doesn’t seem possible with this type of feeding apparatus. But what other nutrition is there for the fly to suck up?
Syrphid fly sponging-sucking who knows what from bindweed anthers,
Caledonia, Marion County, OH, June 12, 2008
Columbus OH Roadside
June 7, 2008
Many central Ohio roads are now flanked by a dense monoculture of our most poisonous poisonous plant, poison hemlock, Conium maculatum. (Danger, poison!)
hamlock along road
Poison hemlock (Conium maculatum) along Columbus roadside, June 7, 2007.
This stuff is really toxic. The active ingedient, Conine, is a neurotoxin that blocks an acetylcholine receptor on the neuromuscular junctions of peripheral nerves, causing an ascending muscular paralysis that eventually stills the muscles that enable breathing. The only way to avoid death is to go on artificial ventilation for a few days, until the effects subside. Very small amounts can be lethal! Arghh!
Poison hemlock is famous for having been the self-inflicted method by which the Greek scholar Socrates was executed in 399. His last words, spoken to a friend who tried but wasn’t able to convince him to escape was “Crito, we owe a cock to Asclepias. Please, don’t forget to pay the debt.” Asclepius was the Greek god for curing illness, but Socrates wasn’t hoping for a cure from the hemlock poision. Instead he was regarding death itself as as a cure. A cure for life I guess. Bleak.
The Death of Socrates, by Jacques-Louis David (1787).
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.
poison hemlockQueen Anne’s Lace
Two white flowered umbellifers in Columbus, OH.
Left: poison hemlock, June 7, 2008. Right: Queen Anne’s Lace, July 9, 2006.
An umbel is an inflorescence (flower cluster) that has stalked flowers that are all attached at one point. Most members of the Apiaceae, moreover, bear compound umbels, wherein simple “umbellets” are jointly connected to a single point on the main flowering axis (the peduncle). There might be a whorl of small leaf-like bracts –the involucre –sitting just beneath the connecting point of the stalks of the umbellets The involucre is a major distinction between these two lookalike weeds.The involucre of poison hemlock is a whorl of short simple bracts.
Poison hemlock (Conium maculatum) umbel, showing small simple involucre. June 7, 2008, Columbus, OH.
By contrast the involucre of Queen Anne’s lace is large and pinnately branched.
Queen Anne’s lace (Daucus carota) umbel, showing elaborate involucre.
Stages Pond State Nature Preserve, Pickaway County, OH, July 26, 2003.
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.
hemlock stem beforehemlock stem after
Poison hemlock stem is glaucous! Columbus OH, June 7, 2008.
The stem of Queen Anne’s lace is pubescent with stiff erect hairs.
Queen Anne’s lace (Daucus carota) stem and leaf base,
Stages Pond State Nature Preserve, Pickaway County, OH, July 26, 2003.
June 7, 2008
Linear-leaved Lowland Lookalikes
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.
sweetflag and cat-tail
Sweetflag (Acorus sp.) with a few cat-tails (Typha latifolia), Home Road, Columbus, OH. June 7, 2008.
Besides applying the “smell test,” sweetflag leaves can be differentiated from those of cat-tail by being bright pure-green, while the cat-tail has a slight bluish cast. The sweetflag leaf has a stout raised midvein that cat-tail lacks.
cat-tail and sweetflag leaves
Linear-leaved lowland look-alikesTypha latifolia on the left and sweetflag (Acorus sp.) on the right.
Home Road, Columbus, June 7, 2008.
Sweetflag (Acorus sp.) flower spikes. Home Road, Columbus, June 7, 2008.
Sweetflag flowers are individually small, stalkless, and inserted on an elongate spike-like axis termed a “spadix.” The leafy extension above the spadix is termed a “spathe.”
Flowers of sweetflag, Acorus sp., June 7, 2008
The genus Acorus used to be included within the arum family, Araceae, that includes some interesting Ohio natives such as skunk cabbage (Symplocarpus) and Jack-in-the-pulpit (Arisaema) that have spathe-spadix flower arrangements that are more obvious. Here’s an example of a typical arum. Coincidentally, a friend just asked me about this one in an e-mail (Hi Dave!). It’s called green dragon, Arisaema dracontium. Does it look like a dragon?
green dragongreen dragon flowers
Green dragon, Arisaema dracontium (family Araceae) showing characteristic spathe-and-spadix flower arrangement. Delaware Wildlife Area, Delaware (or maybe Marion) County, OH, May 19, 2008.
June 7, 2008
Fireworks in June
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.
Angelica (Angelica atropurpurea, family Apiaceae), Home Rd., Columbus, OH, June 7, 2008
Members of the Apiaceae typically have compound leaves with an expanded base that wraps aound the stem. Angelica atropurpurea, Home Rd., Columbus, OH, June 7, 2008.
Apiaceae flowers are individually small, with drab white, greenish, or yellow coloration. There are no flashy colors in this family. These ants visiting angelica seemed to be both drinking nectar and eating pollen.
Ants on angelica, Home Rd., Columbus, OH, June 7, 2008.