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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Spring Wildflowers III

Caltha palustris

Marsh Marigold

Marsh Marigold (Calthus palustris) grows throughout the state. In fact, it grows around the world in the temperate regions of the northern hemisphere. It likes to grow were its roots are wet. It blooms in May in the Lower Peninsula and into June in the Upper. Its showy flowers can often be seen from a moving car.

Stylophorum diphyllum

Yellow Wood Poppy

Yellow Wood Poppy also called Celandine (Stylophorum diphyllum) occurs in the Lower Peninsula. Blooming in May, the attractive flowers provide yellow highlights in the rich woods. Later it sets hairy seedpods. Its flowers are greater than 17mm and it has opposite leaves. The similar, imported, yellow-flowered, Celandine (Chelidonium majus) has flowers less than 14mm across, alternate leaves, and smooth seedpods. Although it is smaller than the Yellow Wood Poppy it is sometimes called Greater Celandine from a translation of its scientific name.

Stylophorum diphyllum

Yellow Wood Poppy

Wild Geranium (Geranium maculatum) is a common woodland species in southern Michigan. Eleven species from this genus have been recorded from Michigan, but this one has the showiest flowers. The common garden geranium is from the genus Pelargonium that has many species and hybrids in cultivation.

Geranium maculatum

Wild Geranium

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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Anther Variations in Yellow Trout Lily

Last weekend at the Royal Oak Nature Society’s Open House I was asked about the two types of Yellow Trout Lily (Erythronium americanum) that grow in Tenhave Woods. Some plants have yellow anthers and other plants have brown to red anthers.

Erythronium americanum

Anther Color in Yellow Trout Lily Tenhave Woods

I did a search of the literature and found Oliver Farwell’s 1938 description of Erythronium americanum var. rubrum. He writes, “In this region we have two very conspicuous variations of this species that could readily be differentiated by size of plants and flowers alone. The smaller one, with green leaves mottled with paler green or dirty white, with mostly entire stigmas, and with yellow stamens, is the typical variety of the species; scapes are from 5 to 10 inches high, with a yellow flower 0.75 [19mm] -1.35 inches [34mm]  long….The larger variety [var. rubrum] is one third to one half larger in all its parts; the stigma is usually three-lobed, and the stamens are red, the leaves being mottled with brownish purple” (Oliver A. Farwell, Notes on the Michigan Flora VII, in Papers of the Michigan Academy of Science, Arts, and Letters Vol. XXIII, 1937. Published 1938). His plants were collected in Houghton County in Michigan’s Upper Peninsula. There is no doubt that these entities are the two types we have in Tenhave Woods. What I don’t know is the significance of them.

Erythronium americanum

Yellow Trout Lily with Yellow Anthers, Tenhave Woods

Erythronium americanum

Yellow Trout Lily with Reddish-brown Anthers, Genesee Co., Michigan

Fernald, in the eighth edition of Gray’s Manual of Botany, writes regarding this species “highly variable, needing more study.” He does not mention Farwell’s var. rubrum although he must have known about the name. Gleason, in the New Britton and Brown Illustrated Flora states, “races with yellow and with brown-red anthers exist and some students of the genus have suspected that two species are included.” Fassett in his Spring Flora of Wisconsin merely comments, “anthers yellow or reddish-brown”. Fassett was well known for using names for minor forms of plants but ignored Farwell’s named variety. The Flora of North America states, “filaments yellow, lanceolate; anthers yellow, chestnut brown, or lavender; pollen yellow or brown” but makes no taxonomic distinction.

The plants appear to be distinct and found over a large range. More study is needed including, marking plants to discover if the anther color is consistent from year to year, taking measurement to see if there is a size difference, looking for other characters to distinguish the plants, and looking for intermediate plants. Farwell’s
characters of leaf mottling and size do not hold true in my limited test
sample. After study, we can then hopefully determine if the plants are distinct species, subspecies, varieties, or forms.

Flower Parts

Flower Parts

Here is a review of the parts of a flower. Anther: the part that produces pollen. Filament: the thin structure that supports the anther. The anther and filament combine to make up the stamen. Stigma: the sticky part that receives the pollen. Style: the structure that supports the stigma. Ovary: where the seeds develop. The stigma, style, and ovary combine to make up the pistil.

 

 

Copyright 2013 by Donald Drife

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