Wednesday, August 27, 2014

Wildflowers of 2014 - #206 through #217

I spent much of last week preparing materials for the upcoming school year.  As a result, I am a little behind on writing about my wildflower finds.  The following twelve species were all found on Monday 18 August 2014 at Mission Creek Woodland Park.

Wildflowers of 2014 - #206 Swamp Thistle (Cirsium muticum)

The first flower of the day was the third thistle (Cirsium) species that I found this year - Swamp Thistle (Cirsium muticum).  Unlike species #150 Canada Thistle (C. arvense) and #178 Bull Thistle (C. vulgare), Swamp Thistle is native to Michigan.  As its name suggests, Swamp Thistle is found in wet soils along shorelines, riverbanks, sedge meadows, and conifer swamps (rarely hardwood swamps).  It is found across eastern North America.  This species is not listed  for Isabella County on the Michigan Flora database.

Swamp Thistle in a typical habitat (cedar swamp)

Swamp Thistle is easy to identify.  It grows to a height of 2 to 10 feet tall.  The stems of the plant have few spines along their length.  The plant's leaves are deeply lobed and arranged alternately along the stem.

Swamp Thistle - a closer view of the plant's leaves and stem

The plant is a biennial and flowers in its second year.  The flower is the distinguishing characteristic of this plant.  Swamp Thistle flowers are flat-topped, purple-pink, and arrange either singly or in a group of 2-5 flowers at the top of the stem.  The flowers are at the top of a rounded bract.  What makes this thistle distinctive is the lack of spines on the bract.  This plant flowers from mid-Summer into fall.

Swamp Thistle - note the lack of spines on the flower's bracts

Wildflowers of 2014 -#207 Flat-topped White Aster (Doellingeria umbellata)

The second flower of the day was my first Aster species of the year - Flat-topped White Aster (Doellingeria umbellata).  All aster species used to be lumped under the genus Aster, but they have been sorted into several different genera over the past decade.  The scientific name for this species used to be Aster umbellatus. Flat-topped White Aster is the only member of its genus found in Michigan.  It has a range from Alberta to Quebec south to Mississippi, Alabama, and Georgia.  The heart of its range is the Northeast and Great Lakes with smaller populations elsewhere.  It prefers moist, low places.

Flat-topped White Aster (Doellingeria umbellata)

Flat-topped White Aster can grow to a height of 3 to 7 feet.  It has a single stem that branches at the top into a flat-topped flowering cluster.  The plant's leaves are arranged alternately along the stem.  The leaves are simple with smooth margins.  The leaves are oval-shaped and taper to a point at both ends.  The leaves do not have stalks.

Flat-topped White Aster - note the pointed, oval-shaped, alternately arranged leaves with smooth margins

The individual flowers of Flat-topped White Aster are 1/2 to 3/4 inches across.  The flat-topped clusters (panicles) can be several inches across.  Individual flowers are made up of a yellow center made of many disc flowers surrounded by a ring of 7 to 14 ray flowers (petals).  The centers fade to a purple color when pollinated.  These flowers bloom from late summer into fall.

Flat-topped White Aster - note the yellow disc and relatively few (7 to 14) rays on each flowerhead

Wildflowers of 2014 - #208 Swamp Lousewort (Pedicularis lanceolata)

The third flower of the day was Swamp Lousewort (Pedicularis lanceolata).  This plant is also known as Swamp Betony.  As its name indicates, Swamp Lousewort grows in wet soils found along shorelines, swamps, wet meadows, etc..  It has been recorded in 25 states and the Canadian provinces of Ontario and Manitoba.  There is a related species Wood Betony (P. Canadensis) that prefers dry soils.

Swamp Lousewort - note the fern-like leaves and creamy flowers

Swamp Lousewort grows up to 2 1/2 feet tall.  It has has leaves that are mostly arranged in opposite pairs.  Each leaf may be up to 5 inches long and 1 1/4 inches wide.  The leaves are deeply lobed along their margins (pinnatefid) and resemble the leaves of ferns.

Swamp Lousewort - a closer view of the hooded flowers

Swamp Lousewort flowers are arranged in a spike at the top of the plant.  The flowers are white or cream colored  and have a tubular shape with the top of the tube forming a upper lip or hood.  The individual flowers are approximately 3/4 inch long. This flower design limits the types of pollinators that can access the plant. 

Wildflowers of 2014 - #209 Hog-peanut (Amphicarpaea bracteata)

The next flower is Hog-peanut (Amphicarpaea bracteata).  This small vine (up to 5 feet long) climbs by twining around nearby objects.  This plant is able to grow in a variety of habitats ranging from oak-hickory forest with dry sandy soil to swamps.  It is found mainly in the southern half of Michigan's Lower Peninsula with another population with a separate population in the western half of the Upper Peninsula.  It is found in every state east of the Mississippi River and as far west as eastern Wyoming and Montana.

Hog Peanut - note the small pink flowers and the way the vine wraps around nearby vegetation

Hog-peanut plants have alternate leaves with three leaflets.  The leaflets are rounded at the base and pointed at the tips.  The plants small pink or white flowers grow from the leaf axils.  The flowers are 1/2 to 5/8 inches long.  The flowers have a typical pea-flower shape with 5 petals (a banner, two wings, and pair of petals fused into a keel).

Hog Peanut - note the trifoliate (three-part) leaf

Wildflowers of 2014 - #210 Great Blue Lobelia (Lobelia siphilitica)

The fifth flower of the day was Great Blue Lobelia (Lobelia siphilitica).  This plant reaches heights of four feet and has lavender-blue to dark-blue tubular flowers.  It can be found in moist soils across much of the eastern two-thirds of the United States and Canada.

Great Blue Lobelia (Lobelia siphilitica)

Great Blue Lobelia - a closer view of the flowering spike

I wrote a profile of Great Blue Lobelia in November 2013 - please look here for more information.

Wildflowers of 2014 - #211 Rough-leaved Goldenrod (Solidago patula)

When most people think of goldenrods, they think of species that grow in dry to moist open habitats.  Most people do not associate goldenrods with either woodlands or wetlands, but there are species that grow in both.  Several of these species can be found growing at Mission Creek Park including Rough-leaved Goldenrod (Solidago patula).  This plant is considered an obligate wetland species - meaning it is only found in wet habitats such as swamps and wet meadows. Also known as Swamp Goldenrod, this species can be found east of a line running from eastern Texas to Wisconsin.  In Michigan it is found almost exclusively in the Lower Peninsula.

Rough-leaved Goldenrod in the Red Maple Swamp at Mission Creek Park

Rough-leaved Goldenrod has the golden yellow flowers that you would expect a goldenrod to have.  The individual flowers are small, measuring 1/8 inch.  The flowers along one side of spreading branches that form a pyramid-shaped panicle.

Rough-leaved Goldenrod flower panicle

Rough-leaved Goldenrod - a closer view of the individual flowers

The leaves of Rough-leaved goldenrod are large (up to 16 inches long); oval or elliptical in shape, tapering to the point and the stem; and as expected from the name the upper surface of the leaves is rough textured.  The lower surface of the leaf is smooth.  The rough textured leaves and its habit of growing in wetlands make this one of the easier goldenrod species to identify.

Rough-leaved Goldenrod leaf - if you look closely you can see the rough, sandpaper-like texture of leaf's upper surface

Wildflowers of 2014 - #212 White Snakeroot (Ageratina altissima)

White Snakeroot (Ageratina altissima) was the next flower that I found.  While this species is more typically found in wooded upland habitats it can also be found along the margins of swamps, as it is at Mission Creek Park.  It has a range across the eastern United States, being found in every state east of a line running from  North Dakota to Texas.  It is also found in the Canadian provinces of Ontario, Quebec, New Brunswick, and Nova Scotia.  There is also a population recorded in Nunavut.

A small colony of White Snakeroot (Ageratina altissima)

White Snakeroot bears a resemblance to plants in the Boneset (Eupatorium) family and used to classified as Eupatorium rugosum.  Like the Bonesets this plant has small white flowers.  The flowers measure 1/8 to 1/4 inch across and are arranged in rounded clusters of 12 to 30 flowers.

White Snakeroot - a closer view of the small white flowers

The leaves of White Snakeroot  are variable in shape and may be narrow ovals, wide ovals, or heart-shaped.  They are pointed at the tip and have sharply toothed margins.  Unlike Bonesets, the leaves of White Snakeroot have stalks.  The leaves are arranged in opposite pairs.  White Snakeroot plants may reach heights of 1 to 5 feet.

White Snakeroot - note the opposite pairs of leaves and the flat-topped cluster of flowers

This plant is toxic and can cause a fatal illness in cattle.  If the cattle are milked after consuming White Snakeroot, the toxins can be passed on to humans.  This "Milk Sickness" claimed the lives of many people in early American history, including Abraham Lincoln's mother.

Wildflowers of 2014 - #213 Thin-leafed Sunflower (Helianthus decapetalus)

The eighth flower of the day is from a group of plants that are not usually associated with woodlands, but several species of sunflowers are commonly founded in wooded habitats including the Thin-leaved Sunflower (Helianthus decapetalus).

Thin-leaved Sunflower (Helianthus decapetalus)

The leaves of Thin-leaved Sunflower can be used to differentiate this species from other woodland sunflower species.  All of its leaves are arranged in alternate pairs - this distinguished it from Woodland Sunflower (H. divaricatus) which has both opposite (lower) and alternate (upper) leaves.  Rough-leaved Sunflower (H. strumosa) shares with Thin-leaved Sunflower the characteristic of having only opposite leaves, but the leave differ in a couple areas.  The leaves of Thin-leaved Sunflower are smooth while those of Rough-leaved sunflower are (surprise!) rough to the touch.  The leaves of Thin-leaved Sunflower are also sharply toothed and have long stalks - those of Rough-leaved sunflower are shallowly toothed and have short stalks.

Thin-leaved Sunflower leaf - note the long petioles (stems) and sharply toothed margin

The flowers of Thin-leaved Sunflower have a yellow central disc typically surrounded by 8 to 15 yellow rays.  Each plant has only one flower head.  The heads measure 1 1/4 to 3 3/4 inches across.

Thin-leaved Sunflower - flowers from this plant normally have 8 to 15 petals, this one only has six

Wildflowers of 2014 - #214 Mad-dog Skullcap (Scutellaria lateriflora)

While some wildflowers have names that are perfect descriptors, like Rough-leaved Goldenrod and Swamp Thistle; other species have names that appear to be nonsense such as the next species - Mad-dog Skullcap (Scutellaria lateriflora).

Mad-dog Skullcap (Scutellaria laterifolia)

Skullcaps are members of the Mint Family (Lamiaceae).  There are seven species of Skullcaps that are considered native to Michigan, however only two of these Mad-Dog and Marsh Skullcap (S. galericulata) are common.  Skullcaps are named because the shape of their seedpods resembles that of a skullcap.  Mad-Dog Skullcap was named after the mistaken belief that the plant either could cure rabies or was a cause of rabies.

Mad-dog Skullcap - note the small size of the tubular flowers

Mad-Dog Skullcap grows in rich, moist soils of swamps, woodlands, and meadows.  It can grow to heights of up to 36 inches but is usually 12 to 18 inches tall.  The plants leaves are oval with pointed tips, arranged in opposite pairs, and have toothed margins.  The plants flowers are pale blue, lavender, or white; tube shaped with a short upper lip and a larger lower lip; and arranged on a raceme (spike) that grows from the leaf axils.  The flowers are small and only measure 1/8 to 1/4 inch long.

Wildflowers of 2014 - #215 Purple Coneflower (Echinacea purpurea)

Finding the next species was a surprise for me.  In more than a decade of recording the flowers in Mt. Pleasant's parks system I have never found a Purple Coneflower (Echinacea purpurea) growing wild until now.  This plant is commonly planted in gardens and prairie restorations.  It is probably not native to Michigan.  I found one bloom at the base of the sledding hill at Mission Creek surrounded by Spotted Joe-pye Weed, Boneset, and Goldenrods.  I suspect that this plant is the result either of a seed being dropped by a bird or it was contained in fill dirt that was used to extend the sledding hill in recent years.

A single Purple Coneflower bloom at Mission Creek Park

Purple Coneflower is easily identifiable by its cone-shaped central disc surrounded by drooping purple ray flowers (petals).  The flowerheads may be between 2 and 4 inches across.  Individual plants may grow to a height of 4 feet.  The plant's leaves are up to 6 inches long and three inches wide.  They may be arranged either in opposite pairs or alternately along the stem.

Wildflowers of 2014 - #216 Horseweed (Conyza canadensis)

The next species is a common weed of disturbed soils such as roadsides, fields, and pastures.  Horseweed (Conyza canadensis) is generally considered native to North America, but it has naturalized in Europe.  This plant is found in all fifty states.  It is native in the Lower Forty-eight and has been introduced to Alaska and Hawaii.

Horseweed - a common weed of disturbed spaces

Horseweed plants have a single unbranching stem that can grow up to seven feet tall, but it can flower when the plant is as short as a few inches tall.  The flowers of Horseweed grow on long upward-growing panicles (branches) that form a pyramid or plume-shaped inflorescence.  The individual flowers are small (less than 1/8 inch) and 20 to 40 white to pink rays (petals) surrounding a yellow central disc.  A large plant may have several hundred individual flower heads.

Horseweed - a closer view of the flower heads

Wildflowers of 2014 - #217 Common Ragweed (Ambrosia artemisifolia)

The final flower of the day was Common Ragweed (Ambrosia artemisifolia).  This non-descript plant with its spikes of small greenish flowers is responsible for many seasonal allergies.  Also known as Annual Ragweed, this plant can be found across most of North America both as a native and an introduced species.  It has been recorded in almost every county in Michigan.  Common Ragweed grows in a variety of habitats including fields, roadsides, lawns, meadows, savannahs, and woodland edges.  It is more common in dry soils than in wet ones.

Common Ragweed (Ambrosia artemisifolia)

Common Ragweed plants grow to a height of up to 36 inches, but they are rarely noticed because of their small flowers.  The flowers grow on elongated spikes at the top of the plant.  The petals measure only 1/4 inch across and lack petals.  The flowers are green but turn yellowish-green to brown after pollination.  The plant does not need to be showy because it relies on the wind for pollination rather than insects.  The leaves of Common Ragweed are deeply lobed, oval, or elliptical and arranged both as opposite pairs (lower) and alternately (upper).

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