Monthly Archives: November 2015

Rope dodder (Cuscuta glomerata)

rope dodder

Rope dodder (Cuscuta glomerata) is an annual herbaceous vine that parasitizes the above-ground portion of other plants. It is considered a noxious weed in the United States and a restricted weed seed in Minnesota, but is listed as threatened in Florida and is a Special Concern species in Wisconsin.

In the spring a seed produces a single, slender, fast-growing stem, and a single root. The root is for anchoring only. It does not absorb nutrients and withers away after the stem attaches to a host plant. The stem lives solely on the nutrients stored in the embryo. It must find and attach to a host plant in 5 to 10 days or it will die. It seeks a compatible host by detecting and growing toward specific airborne volatile organic compounds. When it encounters another plant it wraps around it. If the plant is a suitable host the dodder stem will produce sucker-like, specialized roots (haustoria) that penetrate and draw nutrients from the host plant’s tissue. As it continues to grow it becomes more robust and climbs the host, twining in a counter-clockwise spiral.

From May to early July rope dodder looks like orange tangled string. In July it produces flowers on parts of the stem that are tightly appressed and attached to a host plant. The inflorescence is a dense, rope-like mass of tiny flowers wound spirally around the stem of the host.

There are at least 7 species of dodder in Minnesota. The dense, rope-like inflorescence distinguishes this from all other dodders.

Elm sawfly (Cimbex americana)

elm sawfly

There are about 9,000 living species of sawflies worldwide. Elm sawfly (Cimbex americana) is the largest sawfly in North America. Adults are found in woodlands across the continent from mid-May to mid-August. As the common name suggests, they feed mostly on elm and willow, but also other hardwoods including maple, birch, and American basswood. Larvae feed on the leaves. Adults use their powerful mandibles to cut horizontal gashes in the bark of twigs and small branchlets in order to feed on sap. They sometimes girdle the limb, causing it to die. They can cause sporadic defoliation but are not considered forest pests.

Sawflies are not flies. True flies (order Diptera) have just one pair of wings. Sawflies have two pairs of wings and are more closely related to ants, bees, and wasps (order Hymenoptera). Adults are distinguished by the parallel-sided body (not waisted like a wasp), and by special structures that help hold the forewings in place when at rest. Larvae are distinguished by six or more pairs or leg-like structures on the abdomen, and a smooth head with no cleavage line.

Elm sawfly is identified by the large size and orange, slightly clubbed antennae with 7 or fewer segments.

Eastern red bat (Lasiurus borealis)

eastern red bat

Eastern red bat (Lasiurus borealis) is a medium-sized hairy-tailed bat. In their definitive work on eastern mammals, John O. Whitaker, Jr., and William J. Hamilton, Jr. describe it as “one of the most beautiful of all American bats.” It is widespread in Minnesota but not common. It is found in trees near open areas.

During the day they hang by their feet in a tree or shrub with dense foliage above and to the sides but clear below, leaving a clear flight path. They for just a few hours beginning at dusk. They locate their prey both by echolocation and by sight. Males and females have different summer ranges. They are solitary individuals but come together to migrate in flocks of up to several hundred individuals. They head south for the winter but their wintering range is unknown.

Bats are important vectors of the rabies virus but rabid bats pose little threat to humans. They are passive, will not attack, and will not bite unless handled.

Eastern red bat is named for the brick-red fur of the male. It is further distinguished from other bats in Minnesota by white shoulder patches, long tail not extending beyond the wing-like flight membrane, flight membrane near the tail densely furry above, tail hairy above, and the projection partially covering the ear opening hairy at the base.

Witches’ Butter (Tremella mesenterica)

Witches’ Butter

Photo by Heather Ellis

The cycle of nature dictates that dead trees, branches, and twigs in wooded areas become hosts to wood-rotting fungi. These fungi are saprobic, obtaining their nutrients from dead and decaying wood. Some of these fungi are themselves hosts to other fungi.

Witches’ Butter (Tremella mesenterica), a very common and widespread jelly fungus, parasitizes wood-rotting crust fungi in the genus Peniophora. It can be found during wet periods year-round but especially in late fall, singly or in groups, on logs, branches, and twigs of oaks and other hardwoods. The wood on which it is found may be fallen or still on the tree but is always dead and usually has the bark still attached.

When young and fresh the fruiting body is one or more stemless, gelatinous but tough, ¾″ to 4″ wide, 1″ to 2″ in height lobes and folds. The lobes are translucent, shiny, and pale orangish-yellow to bright yellowish-orange. When clustered, they fuse together and resemble an exposed brain. They are mostly water. In wet conditions they swell and lose shape, looking like a dollop of melting butter. When they begin to dry they become darker orange, more opaque, and smaller. In dry conditions they become dark orange, shriveled up, hard, and brittle. Sometimes they collapse into an inconspicuous film when they dry, but will revive with the next wet weather. It is not poisonous but cooking it will release the water and leave little to eat.

Witches’ Butter is distinguished from other jelly fungi by lobes that are thin, broad, stemless, yellowish-orange, shiny, folded, and brain-like in appearance when clustered; by its occurrence on logs, branches, and twigs of hardwoods; by its shriveling when dry; and by its host Peniophora.

True Tinder Polypore (Fomes fomentarius)

True Tinder Polypore

Anyone who spends time in the woods in the northern half of North America is likely come across a hoof-shaped fungus growing on the side of a tree or log. One of the most common and widespread hoof fungi is True Tinder Polypore (Fomes fomentarius). It is usually found on birch on a live tree or a standing or fallen dead tree. An individual conk (the hoof-shaped fruiting body) can survive for years, even decades, forming a new ridge or furrow each year.

True Tinder Polypore gets its name from its most common usage, as tinder for starting fires. Otzi the Iceman, the 5,000-year-old mummy found in the Alps in 1991, was carrying four pieces of it.

This species can easily be confused with another birch-loving fungus, False Tinder Fungus (Phellinus igniarius). True Tinder Polypore is distinguished by the lighter, uncracked upper surface of older specimens; whitish margin of actively growing layer and underside; pore tubes that are not layered; and lack of white threads running through the cut flesh.

green-faced clubtail (Gomphus viridifrons)

green-faced clubtail

Green-faced clubtail (Gomphus viridifrons) is an early season, medium-sized clubtail. While it is more common in the northeast than in Minnesota, it is uncommon and considered rare over most of its range. It is found from mid-May to mid-July near rapid medium streams and rivers with gravel, silt, sand, and rocks on the bottom. Males are most active in late afternoon, especially under cloud cover.

Green-faced clubtail is distinguished by the face with only light markings, missing middle stripe on the side of the thorax, unusually small abdominal spots, no spots on abdominal segments 8 through 10, and abdominal segment 9 shorter than segment 8.

Smoky Polypore (Bjerkandera adusta)

Smoky Polypore

Smoky Polypore (Bjerkandera adusta) is a widespread and fairly common bracket fungus. It is found in dense, overlapping rows or fused clusters on dead hardwoods. It is rarely found on conifers. It usually takes the form of bracket on the side of a tree or log but occasionally appears as a crust on the underside of a dead branch. It is found year-round but usually appears after fall rains.

The species name adjusta means scorched, and another common name for the mushroom is Scorched Bracket. This refers to the blackened margins on mature and older specimens, the most distinguishing feature of the mushroom when encountered in the field.

Smokey Polypore can easily be mistaken for other bracket fungi, including the much more common Turkey Tail. Smokey Polypore is distinguished by the weakly zoned upper surface in shades of gray and brown, the margins turning brown to black on mature and older specimens; and the gray underside of mature specimens.

Blackberry lily (Iris domestica)

blackberry lily

Blackberry lily (Iris domestica) is a popular garden plant from Asia that has escaped cultivation in North America. It is now widespread in eastern and central United States but scattered and still uncommon. It has been recorded only twice in Minnesota: once, date unknown but prior to 1991, in Waseca, where it was planted and escaped cultivation; and once on 8/8/2014 in Baker Park Reserve in Hennepin County.

The common name of this plant is a misnomer. It is an iris, family Iridaceae, not a lily, family Liliaceae. It gets its name from the lily-like appearance of the flowers and the blackberry-like appearance of the seed clusters. It blooms from June to July and is typically found on hillsides, pastures, woodland openings, thickets, roadsides, old fields, old homesteads, and disturbed areas. The flowers bloom from dawn to dusk and last only a single day.

At different times in its development, blackberry lily is similar in appearance to some of our native lilies and irises. It is distinguished by a combination of the following characteristics: sword-like basal leaves; alternate, overlapping stem leaves; flowers held erect or horizontal, not hanging downward; sepals and petals widely spreading, not curved backward; and clusters of black seeds that look similar to blackberries.