Brown Marmorated Stink Bug

I recently found a stink bug in my kitchen. It was a Brown Marmorated Stink Bug (Halyomorpha halys). This invasive insect is native to Japan, Korea and China. The first North America record was from Allentown, Pennsylvania in 1998 and it reached Michigan in 2011.

Halyomorpha halys

Brown Marmorated Stink Bug

The adults overwinter in houses, barns, garages, and outbuildings. Adults are 12-16mm [1/2-5/8 inch] long and shaped like a shield. Their antennae are dark with light bands. Light spots are also found on the edges of their bodies. This is the only species of stink bug commonly found inside a house during our Michigan winter. It can occur by the hundreds in some homes.

Halyomorpha halys

Brown Marmorated Stink Bug

Brown Marmorated Stink Bugs will not bite humans. They can be a major pest on fruit trees and damage the leaves and fruit of apples, pears, peaches, cherries, corn, tomatoes, peppers, soybeans, and others. Luckily they only raise one brood in Michigan.
Copyright 2017 by Donald Drife

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Broad-leaved Helleborine’s Look-a-likes

Coeloglossum viride

Long-bracted Orchid L & C                                                       Yellow Lady-slipper R (Note hairs)

Many people have posted comments on an earlier blog post about Broad-leaved Helleborine (Epipactis helleborine). There is a lot of confusion regarding the identification of this species. I recently saw a photograph of this orchid identified as Spotted Coral-root  (Corallorhiza maculata). Broad-leaved Helleborine has several color forms and some of the field guides do not account for the variations.

Epipactis helleborine

Close-up of Epipactis flower showing distinctive orchid flower structures

If you have a plant in flower you can recognize it as an orchid because it has three sepals and three petals with one of the petals modified into a lip. The reproductive  organs are fused into a column. The leaves are parallel veined. (Note: Sepals are the outer covering of a flower bud. Petals are inside of the bud.)

Broad-leaved Helleborine’s flowers are about 15mm (5/8 inches) across and the lip is turned in at the tip.

Epipactis helleborine

Smooth leaves and stems of Broad-leaved Helleborine

When not flowering Broad-leaved Helleborine is commonly mistaken for one of the lady-slippers but its leaves and stem are smooth. Lady-slippers (Cypripedium spp.) have hairy leaves and stems. Helleborine normally has more leaves than a lady-slipper.

Long-bracted Orchid (Coeloglossum viride) has smaller flowers with notched lips and is not as coarse a plant as hellebore. It grows in natural areas and I have never seen it invading a garden.

Epipactis helleborine

Root of Broad-leaved Helleborine showing growth bud and side view of flower

While this is not a gardening blog many people ask about controlling this species. The only way I know is to try to dig out the plant. If you leave any of the fleshy root behind it will come back.  Note the growth bud for next year’s plant in the photo. Most orchid species have fleshy roots so please make sure you have the plant correctly identified before you dig. My earlier blog post showed this species growing with domestic Viburnum and, in spite of repeated digging, that colony is still growing. Plants appeared in my wildflower garden, but died out without any interference from me.

Broad-leaved Helleborine is probably growing in every county in the state. Learn the plant when it is flowering so you can identify it later in the year.
Copyright 2016 by Donald Drife

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Japanese Knotweed

Fallopia japonica

Japanese Knotweed leaves and flowers with Monarch Butterfly

Japanese Knotweed (Fallopia japonica) also called (Polygonum cuspidatum) is identified by its jointed stem, with a whitish bloom, that can be 20mm (3/4 inch) in diameter. Large, alternate leaves, with pointed tips are also distinctive. Its flowers are white and normally held upright in short inflorescences. The seeds are three parted and thankfully not all of them are fertile.

Fallopia japonica

Japanese Knotweed flowers and seeds

Fallopia japonica

Japanese Knotweed

This plant has a hollow stem and is also called Michigan-Bamboo. It grows up to three meters tall (10-feet) and forms a dense monoculture. I have seen colonies that cover several acres. It can spread by seed or grow from sections of the stem or roots. It is impossible to dig out a large colony because even a small section of root re-sprouts.

Fallopia japonica

Japanese Knotweed in field

In central lower Michigan it is called bee-plant. I saw a large colony of it with numerous bees and wasps feeding on it. Eight Monarch butterflies nectared there. However, its period of nectar production is short and many native plants are better nectar sources. The DNR is correct in prohibiting the importing or sale of this plant. It should be destroyed wherever it is found. This is primarily an identification blog but information on the control of this species can be found on the DNR’s website.

Fallopia japonica

Japanese Knotweed

Japanese Knotweed was first recorded in the wild in Michigan in 1919. It is now found throughout the state. I have started to see it in central lower Michigan were it previously was absent. It is becoming common in all parts of the state and will prove to be a serious pest that is difficult to control.
Copyright 2015 by Donald Drife

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Pale Swallow-wort: Another Invasive to Watch Out For

Vincetoxicum rossicum

Pale Swallow-wort

Pale Swallow-wort (Vincetoxicum rossicum) also called European Swallow-wort or Dog-strangling Vine is an invasive species moving into southern Michigan. Dr. Reznicek writes, “East of Michigan, this species has become a terrible invasive; it should be stamped out wherever observed.”  It was first recorded from Michigan in 1968 from Berrien County.

Vincetoxicum rossicum

Pale Swallow-wort showing leaves and seedpods

It is a vine in the Dogbane Family (Apocynaceae) that includes our Milkweed species. When not flowering it resembles Bittersweet (Celastrus spp.) but can easily be distinguished by its opposite leaves (Bittersweet has alternate leaves). Flowers are five petaled with the petals longer than wide. Normally they are pale pink but burgundy or dark brown flowers occur. It has narrow, pointed pods resembling true Milkweeds (Asclepius spp.).

Vincetoxicum rossicum

Pale Swallow-wort showing growth habit with opposite leaves and a closeup of flowers

Black Swallow-wort (Vincetoxicum nigrum) is another invasive similar to Pale Swallow-wort. Its petals are hairy on top and about as long as wide. It was first recorded from Michigan in the 1880s.

This aggressive plant will take over a field by choking out competing vegetation. It will out compete our native Milkweeds. This plant also impacts Monarch butterflies because it is toxic to Monarch larva. Monarchs will lay eggs on this species but they don’t survive to adulthood. Pale Swallow-wort appears to be allelopathic meaning that it alters the soil chemistry so seed from other species can’t germinate.

I’d like to thank John DeLisle from Natural Community Services for providing location information.
Copyright 2015 by Donald Drife

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Glossy Buckthorn in Michigan

Frangula alnus

Glossy Buckthorn leaves & fruit

Glossy Buckthorn (Frangula alnus) is also called (Rhamnus frangula). It is a shrub or small tree and aggressively invades wetlands. Shiny, dark green, untoothed, alternate leaves with 7 to 9 pairs of inset veins are characteristics of this species. Its fruit is black when ripe.

Frangula alnus

L-Glossy Buckthorn bark R-Choke Cherry bark

Glossy buckthorn bark is similar to young cherry bark with white lenticels. Most of the time Glossy Buckthorn lenticels are almost round. Cherry lenticels are long lines parallel to the ground. The inner bark on Glossy Buckthorn is orange, on cherries it is reddish to dark brown. Glossy Buckthorn’s buds are rust-colored and naked. They are covered by leaf remnants. The slender twigs are tipped with velvet-like hairs. Twigs never have a thorn at their tips or toothed leaves which are characteristics of Common Buckthorn.

Frangula alnus

Glossy Buckthorn twig showing fine hairs

Glossy Buckthorn can rapidly invade a fen or wetlands. Seedlings often cover the ground. As with many invasive species Glossy Buckthorn leafs out early and stays green late in the fall. I have seen fruiting plants only .6m (2 feet) tall. It will fruit in its second year if conditions are good. The species is now found throughout Michigan and steps to eradicate it should be taken wherever it is found.

Frangula alnus

Glossy Buckthorn seedlings covering the ground

Copyright 2015 by Donald Drife

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A Weedy Orchid (Epipactis helleborine)

Broad-leaved Helleborine (Epipactis helleborine) is a European Orchid that is invading many woodlots and gardens in Michigan. In 1968, Ed Voss wrote an article for the Michigan Audubon Newsletter titled “A Weedy Orchid?” Ed’s prediction proved to be correct so I removed the question mark from my title.

Epipactis helleborine

Profile of flower, an opening flower showing the green sepals which form the outer bud covering, close-up showing droplets of nectar

Imported for its supposed medicinal values, it has colonized much of the state. The oldest specimen for the state was collected in 1919, in Berrien Co., in the southwest corner of the state. In the 1930s it was found on the campus of Michigan State. When Fred Case wrote the first edition of his Orchids of the Western Great Lakes Region this was one of the few orchids growing wild in the state that he had not found. I first found it in 1973 in the lawn of the main branch of the Detroit Public Library. A few weeks later I saw it in the Porcupine Mountains in the Upper Peninsula. It is now recorded from 40 counties in Michigan and doubtlessly occurs in many more.

It is now common in the eastern part of the Upper Peninsula. Large groups can be found in Hartwick Pines State Park especially among the old growth pines. It occurs in Royal Oak’s two Nature Parks. I am starting to see it as a garden weed. My church in Huntington Woods has several hundred plants in one flower bed. Lewiston Lodge in Montmorency Co. has this plant throughout its landscaping. It is a weed that has invaded my garden in Troy. The Michigan State Extension even has a post on controlling this species.

Epipactis helleborine

Plant in natural cedar woods, group of plants in landscape (note domestic viburnums), close-up of spike

The plants look more or less like non-hairy lady’s-slippers. Helleborine is taller and the leaves are only twice as long as they are wide.  In the wild it can be mistaken for Long-bracted Orchid which blooms earlier, has smaller flowers, much longer bracts, and a notched lip.    At least two named flower color forms occur in Michigan. In the common form the flowers are reddish but a green flowered form (f. viridens) often occurs. Sometimes plants with flowers reddish-purple can be seem. Populations can have all color forms.

Epipactis helleborine

Three color forms of Helleborine

This orchid is expanding its range in Michigan and should be an early find for a beginning plant hunter. In time, we will tell whether it proves to be a pest.

Copyright 2013 by Donald Drife

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Common Buckthorn Invading Michigan

Common Buckthorn, also called European Buckthorn, (Rhamnus cathartica) was first collected in Michigan in 1914 but reported by Beal in the 1904 Michigan Flora. Billington in his Shrubs of Michigan, published in 1949, still recommends this species as “an excellent hedge plant;” although, he does admit that the “seeds do germinate easily” and they “create a green carpet under the bushes.” This invasive species should never be planted.

An aggressive invader of many habitats in Michigan, this shade tolerant shrub is choking out many native species. While distributed throughout the state, it is common only in southern Michigan, but seems to be spreading in northern Michigan.

It is one of the the first species to leaf out and one of the last to drop its leaves, resulting in a long growing season and giving it an advantage over our native species. The plants are allelopathic, meaning they inhabit the germination of other species. Their fruit is largely responsible for this characteristic so once the species becomes established it aggressively colonizes the habitat. I have seen colonies of Common Buckthorn that have one large “mother-tree” in its center. The seeds are also epigeal, meaning that they germinate on the ground without having to be buried. This allows large numbers of them to germinate.

Rhamnus cathartica thorns-inner bark

Common Buckthorn thorns and inner bark

The twigs are tipped with a thorn slightly longer than the buds. The buds, and hence the leaves, are sub-opposite but opposite and alternate nodes occur. The nodes shown in the photo are three successive nodes on the same twig. The thorns occur along the branches and are sharp. These distinguish the plant from Wild Black Cherry, and Choke Cherry.

Rhamnus cathartica twig

Common Buckthorn twig

The bark resembles the bark on a Wild Black Cherry but Buckthorn Bark is often redder. Choke Cherry bark is also similar but the lenticels (the large pores) are more prominent in the cherry. If you have doubts, then peel a little of the bark away from a branch and look for the orange inner bark. Most Common Buckthorns have this bark.

Rhamnus cathartica bark

Common Buckthorn bark

The leaves are slightly folded, with fine teeth and 3-5 pairs of prominent recessed veins. They are normally a dark green.

The flowers have four yellow-green petals. Male and female flowers occur on different trees and the female trees outnumber the males. A few male trees in a given population can produce enough pollen to pollinate a large colony. I checked 60 shrubs in one colony looking for male flowers to photograph and could not find any. This same colony heavily fruited that year indicating there was no shortage of pollen.

Rhamnus cathartica Common Buckthorn flowers, leaves, and fruit

Common Buckthorn flowers, leaves, and fruit

The fruit is a three to four seeded drupe that is eaten by birds. A drupe is a fleshy fruit that surrounds a hard pit or pits. Cherries are an example. Most Common Buckthorns fruit heavily, so once a few plants begin to colonize an area it can rapidly take over. The seeds remain in the seed bank for a relatively short period (three to five years). After we cut a large stand in Royal Oak, Michigan, seedlings continued to appear for the next three years.

Michigan Natural Features Inventory has an excellent site on Common Buckthorn.

Copyright 2013 by Donald Drife

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Garlic Mustard (Alliaria petiolata) invading Michigan

Garlic Mustard’s (Alliaria petiolata) native range is Europe. It has invaded North Africa, India, and North America. The first U. S. record is from Long Island in 1868 and it reached Michigan in 1956. Imported for its supposed medicinal values it escaped cultivation and became a serious pest in many woodlands. I saw a large patch of it in 1978 in Rock Cut State Park in northern Illinois. Several acres in size this patch was shading out a colony of Prairie Trillium (Trillium recurvatum). I first saw the plant in Michigan at Warren Dunes State Park in 1981. It was a small patch consisting of a dozen plants. The plant has increased its range and is now found throughout the state.

Alliaria petiolata Garlic Mustard Plants

Garlic Mustard Plants

The plant is easy to identify. It is one to two feet tall (0.3-0.6m), the flowers are white with four petals that narrow at the base, and the leaves are heavily toothed, more or less triangular shape with the veins inset into the upper leaf surface. The seed pods are long and narrow with small ridges, and are similar to native species. They develop quickly, often elongating before the petals drop, and they will continue to develop after the plant is pulled.

Alliaria petiolata  Garlic Mustard Flowers

Garlic Mustard Flowers (note developing seedpods in right hand flowers)

It is a biennial, meaning that it flowers in its second growing season. The basal leaves form the first year and are more rounded than the stem leaves on the flowering plant. Garlic Mustard seed germinates at low temperatures (32 degrees F). This gives the seedlings a head start over other native species.

Alliaria petiolata  Garlic Mustard Basal Leaves

Garlic Mustard Basal Leaves

Garlic Mustard is allelopathic and destroys the connections between native tree seedlings and mycorrhizal fungi (Stinson K. A, Campbell S. A., Powell J. R. Callaway R. M. 2006). This prevents completion from native tree species and perhaps other plants.

Alliaria petiolata Garlic Mustard Leaves

Garlic Mustard Leaves

For additional reading regarding Garlic Mustard and its control, see the U. S. Forest service fact sheet.

Alliaria petiolata  Garlic Mustard Seedpods

Garlic Mustard Seedpods

Copyright 2013 by Donald Drife

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Viburnum Leaf Beetle

Viburnum Leaf Beetle first instar and second instar

Viburnum Leaf Beetle first instar L and second instar R

A native of Europe and Asia the Viburnum Leaf Beetle (Pyrrhalta viburni Paykull was discovered in 1978 in the Ottawa-Hull region of Canada. It was first recorded from the U. S. in 1994 and from Michigan in 2007. Both the larva and the adults feed on the leaves of thin leaved Viburnum species. The insect eats Highbush-Cranberry (Viburnum trilobum), Arrowwood (Viburnum dentatum), Nannyberry (Viburnum lentago), and Black-haw (Viburnum prunifolium), all of these species are native to Michigan. It also eats the imported European highbush-cranberry (Viburnum opulus) and its cultivar, Snowball Bush, and Wayfaring Tree (Viburnum lantana). The thicker leaved Viburnum species do not seem to be a food source.

The larva molts and has three instar stages before dropping to the ground and pupating. The adult emerges and continues to feed on the host plant. The insect overwinters as eggs laid under the bark of the Viburnum.

Viburnum Leaf Beetle third instar and leaf

Viburnum Leaf Beetle third instar and leaf

The photographs are from Troy Michigan. It has defoliated several Viburnums in our garden. Our plants died after being attacked for two successive years. The plant leafed out after the larva destroyed the leaves and the adult beetles again defoliated the plants.

For more information see About.com Gardening

Copyright 2013 by Donald Drife

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Coltsfoot: a potential invasive species?

Tussilago farfara flowers

Coltsfoot flowers

Coltsfoot (Tussilago farfara) is a Eurasian species first collected in Michigan in 1840 (See Michigan Flora Online). I saw it for the first time on, March 15th 1978, in Bald Mountain Recreation Area and then along a road in Jackson County about a week later. I wondered if the plant was invading our natural areas, but almost three decades passed before I saw the plant again. I found a small colony in Crawford County in 2006 and that same year I saw 75 plants in Oakland County at Cummingston Park, in Royal Oak, Michigan. The Cummingston Park patch was wiped out when the pond was enlarged.

Tussilago farfara

Coltsfoot flower and seeds

In 2009, the Crawford County station was in flower on May 2nd. Two weeks earlier it was still covered by winter snow. By May 16th the leaves were developing and it was in seed by May 30th. In 2006, the Crawford County station was about 1 meter (3 feet) square. It has since increased to 1 x 2 meter (3×6 feet).

Tussilago farfara leaves

Coltsfoot leaves

The species might be overlooked especially in northern Michigan because it flowers early. It is currently (May 8th) flowering at the Crawford County (near Grayling) site. However, it can be readily identified by the leaves throughout the summer. The leaves have long petioles (leaf stems), are heart-shaped and a distinctive grayish color underneath. Any species that spreads via both rhizomes and seeds should be watched. Coltsfoot has only been collected in eight counties in Michigan but has spread rapidly east of us. Normally it does not compete with native species, preferring to grow where the soil has been disturbed, but it is now moving into native sites in Pennsylvania. This species should be reported whenever it is found (U.S. Forest Service Plant Database).

Coltsfoot initially was imported into this country for its supposed medicinal properties. The leaves were used to treat coughs and bronchial congestion, but possess a liver toxin. There is no current medical use.
Copyright 2013 by Donald Drife

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