Monday, March 10, 2014

Native Species Profile - Maximilan's Sunflower

The natural range of some species of plants can be difficult to identify because they have been spread outside that natural range by human activities.  One plant that fits this description is Maximilian's Sunflower (Helianthus maximiliani).

Maximilian's Sunflower is found in 38 states from the Atlantic to the Pacific and in 6 Canadian provinces, but its native range is probably the Central Great Plains.  In most states it is found in only a few widely scattered locations.  According to the USDA PLANTS Database, Maximilian's Sunflower is found in counties in southeastern Michigan, several counties in the southwest part of the state, five counties in the northern part of the Lower Peninsula, and in counties across the Upper Peninsula.  It was first collected in Michigan in 1898.  It is not known from any specimens in Mid-Michigan.

Michigan County Distributional Map for Helianthus maximiliani
Michigan range of Maximilian's Sunflower - USDA PLANTS database

These photos are from a colony of the plant growing along a roadside in northern Isabella County, right in the middle of Michigan where the range maps do not show it growing.

Like all sunflowers, the bloom of Maximilian's Sunflower is a composite flower consisting of yellow disk florets surrounded by 15 to 40 yellow ray florets (petals).  The flowers are located near the top of the plant either individually or in small clusters, each with its own short stem.  Flowers may also grow from the axils of the upper leaves - the joint where the leaf connects to the stem.  Individual blooms may be 2 to 5 inches across.  The plant blooms between July and October.

Maximilian's Sunflower - note number of petals (15 - 40)

Maximilian's Sunflower is a perennial plant.  It often forms large colonies, with new members of colonies growing both from the roots of parent plants and from seed.  Individual plants grow from 2 to 10 feet in height - with most plants on the shorter end of this range.  The plant prefers dry soils and often grows best in poor soil types.  In rich soils, the plant grows quickly and droops downward, pulled by its own weight. 

Colony of Maximilian's Sunflower

The leaves and stems of Maximilian's Sunflower are grey-green in color.  The stem is covered with a dense coat of short white "hair".  The leaves of Maximilian's Sunflower are its most distinguishing characteristic.  The leaves are lanceolate (shaped like a lance head - oval tapering to a point at both ends) and may be up to 12 inches long.  The leaves are sessile meaning they lack stalks and are attached directly to the plant's stem.  They are typically arranged alternately along the stem - although a few leaves near the bottom of the stem may be arranged opposite each other.  The leaf margins are smooth or may have a few widely spaced small teeth.  The leaves also fold upward from the midrib into a V-shaped cross-section.  The leaves also curve into an arc from stem to tip.

Maximilian's Sunflower - note folded, V-shaped cross-section of leaves
This plant is important to many wildlife species.  The flowers provide nectar and pollen to many species of insects.  The leaves are grazed by wildlife such as deer and (historically) bison.  The seeds are consumed by many species of seed-eating birds and by small mammals.

Maximilian's Sunflower - note flowers at terminal end of plant and growing from leaf axils

Maximilian's Sunflower is named after an early explorer of the American West.  Prince Alexander Philipp Maximilian zu Wied-Neuwied joined an expedition with the American Fur Company from St. Louis to the Upper Missouri River from 1832 to 1834.  Upon returning to Germany wrote a book detailing his travels.  Prince Maximilian also led an expedition to Brazin from 1815 to 1817.  In addition to Maximilian's sunflower, the Margay (Leopardus wiedii), a species of cat native to Central and South America, and a genus of orchids (Neuwiedia) are also named after the Prince.

Maximilian's Sunflower - note large yellow flowers, grey-green foliage, and folded leaves
Although Maximilian's Sunflower is likely not a native of Michigan, it is a native of North America.  The plant may have been intentionally planted in gardens outside its native range and escaped into the wild.  Its seeds may also have hitchhiked on human transportation.  The two earliest records of this plant in Michigan are both from along railroad lines.  Even today it is most often found along railroads and roadways.  I can speak from experience that this is such an attractive plant that wildflower lovers will stop along the roadway to admire colonies wherever they find them.

Maximilian's Sunflower - note the grey-green color and curved leaves with V-shaped cross-section

Basic Information

Maximilian's Sunflower
Helianthus maximiliani

Height:  2-10’ tall

Habitat:  moist or dry habitats, roadsides, railways, grasslands, savannahs

Flower Color:  yellow

Bloom Time:  July – October

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