Helianthus dalyi Britton

Scientific Name: Helianthus dalyi Britton

Helianthus dalyi Britton

General Information
Usda Symbol	HEDA2
Group	Dicot
Life Cycle	Perennial
Growth Habits	Forb/herb
Native Locations	HEDA2

Plant Guide

Alternate Names

Helianthus dalyi, Helianthus maximilianii, Maximillian sunflower, Maximilian’s sunflower, Michaelmas-daisy.

Uses

Erosion control: Maximilian sunflower has a perennial root crown and rhizomatous root system. Annual stems are produced from underground stems. This growth pattern allows Maximilian sunflower to spread and form dense plant clusters, reinforcing soil and preventing erosion. Ethnobotanic: Native Americans used parts of this plant as sources of food, oil, dye, and thread. Pioneers planted Maximilian sunflowers near their homes to repel mosquitoes and used the blossoms in bathwater to relieve arthritis pain. Sunflower seeds are eaten as snack items and sprinkled on salads and other foods. Industrial products: The natural rubber present in Maximilian sunflower qualifies the plant as a potential source of industrial raw materials. Livestock: Although the protein value of Maximilian sunflower is poor, it is a palatable livestock forage species. It remains green late into the fall and is consumed until the first frost makes it less flavorful. It is plentiful on ranges that are not closely grazed. Moderate grazing can increase the presence of Maximilian sunflower. Ornamental: The bright yellow flowers of Maximilian sunflower make it a popular choice for use in native gardens. It can be utilized as a hedge or natural screen because of its height. Restoration: Maximilian sunflower is used as a conservation planting for habitat development, prairie restoration and landscaping, and range and pasture maintenance. It can be used in filterstrip plantings. It has been used with native grasses in Kansas to revegetate coalmine spoils. Wildlife: Butterflies, beetles, and long- and short-tongued bees consume the nectar or pollen produced the flowers of Maximilian sunflower. Butterfly caterpillars feed on the foliage while moth caterpillars bore through the stems. Upland game birds, small non-game birds, and some waterfowl consume its seeds. Rabbits and groundhogs feed on young plants while elk, mule deer, white-tailed deer, and pronghorn antelope browse and graze older plants. It has poor nutritional value for these species. Habitat and cover are provided to birds and small mammals by individual plant clusters and dense colonies formed with other shrub-like plants.

Description

General: Aster Family (Asteraceae). This native perennial has a stout, rhizomatous root system. It grows from 0.9 m to 2.5 m tall with stems occurring singly or in clusters. The central stem is stout, light green to light red, and covered with short, dense white hairs. Leaves are alternate, up to 30 cm long and 5 cm wide, sessile, narrowly lance-shaped, and folded upward from the central vein. Leaf surfaces are covered with white hairs; margins are smooth or loosely toothed. Short inflorescence stalks emerge from the leaf axils, bearing one composite flower head and one to two leaves. Each inflorescence has two pale green bracts at its base, is 5 to 7 cm in diameter, and has 20 to 40 yellow ray flowers and many yellow disc flowers. Flowering occurs in September and early October. Fruits are achenes that ripen in October and November and are wind or animal dispersed. The characteristic that distinguishes Maximilian sunflower from other Helianthus species is the grayish appearance given off by dense white hairs on the plant. Distribution: Maximilian sunflower is native to the central United States, from Ontario, Michigan, and Ohio, west to Alberta, Montana, Wyoming, and Colorado and south to Texas. It may be sparsely introduced east and west of its native range. For current distribution, please consult the Plant Profile page for this species on the PLANTS Web site (http://plants.usda.gov). Habitat: Maximilian sunflower occurs on rocky upland and loess hill prairies, rocky ledges, and along railways, roadsides, fences, and other disturbed areas. In drier regions, it is found along streams and near wetter areas. In mixed-grass prairies, it is associated with bluestem, switchgrass, Russian thistle, silverberry, milkweed, and snowberry species. In tallgrass prairies, it is associated with big bluestem, switchgrass, Indian grass, heath aster, ironweed, and Canada goldenrod. In floodplain tallgrass prairies, it is associated with prairie cordgrass, spikesedge, Indian grass, big bluestem, switchgrass, compass plant, milkweed, and annual sunflower.

Adaptation

The USDA hardiness zones for Maximilian sunflower are 3 to 9. Although it can grow in a variety of conditions, it prefers moist clay-like soils, soil depths of 50 cm or more, 250 to 1,270 mm annual precipitation, gentle slopes, and full sun. Soil, moisture, and topography can be variable, but Maximilian sunflower will not tolerate shade. It tends to grow very tall in moist rich soil and may become top-heavy when in bloom. Growth is poor on gravel, dense clay, or saline soils. Maximilian sunflower plants are allelopathic. They produce chemicals that hinder the growth of neighboring plants. These chemicals are not harmful to livestock and wildlife.

Establishment

In early winter, rake Maximilian sunflower seeds into loose topsoil and cover with 0.25 to 0.5 inch of soil or mulch. A long cold period is required before germination. The average number of seeds per pound varies by location. The South Dakota Plant Materials Center has listed 250,000 seeds per pound while both the North Carolina Department of Transportation and Texas A&M University report 182,000 seeds per pound. The appropriate seeding rate for pure Maximilian sunflower stands is 5 pounds per acre, allowing space between germinated plants. If used as part of a prairie seed mixture, Maximilian sunflower seeds should be included at a rate of 0.1 to 0.25 pound per acre. Optimal seeding times are November to May in the central Great Plains and January to March in the southern Great Plains. In Nebraska, Maximilian sunflower established best when weeds were controlled mechanically. Seedling vigor is good. Growth occurs in late spring and summer with some flowering by the end of the first season. Most Maximilian sunflower plants are not fully developed until the second season. Plants primarily spread by rhizomes after establishment.

Management

Maximilian sunflower plants growing on rich, fertile sites will grow tall and spindly. Weak stems will cause the plants to fall and can be staked to remain upright. Older stems can be mechanically cut back at the end of the season to make room for new sprouts. Maximilian sunflower exhibits fire tolerance in its dormant stage. Seedlings will emerge on open, post-burned sites from the underground seedbank and rhizomes. Following fire in North Dakota, Maximilian sunflower grew taller, stiffer, and seeded more vigorously. Research suggests that plant performance increases following fire in disturbed, invaded areas but not on undisturbed areas. Fire removes competition and opens up the canopy for Maximilian sunflower in the disturbed areas.

Seeds and Plant Production

Plant Production , Use soil moisture sensors to measure the soil moisture of Helianthus dalyi Britton.

Plant Production

Seeds are ready for collection in late October and November. They are moist stratified for 56 days. Germination occurs at an alternating cycle of 30oC daytime and 15oC nighttime temperatures. The optimum soil temperature for germination is 20oC to 30oC. Seventy percent of seeds will germinate in 7 to 25 days. One-year-old plants sprout new shoots that can be dug up and cut from the parent plant. Division and transplantation should take place in February or March. Cultivars, Improved, and Selected Materials (and area of origin) The USDA NRCS Plant Materials Center has released Maximilian sunflower cultivars ‘Aztec’ and ‘Prairie Gold’ for conservation use. ‘Aztec’ was released for the purposes of wildlife food, livestock forage cover, natural hedges, screens, filterstrips, and as ornamental landscape plants. ‘Prairie Gold’ was released for critical area reseeding and wildlife food plantings. These plant materials are readily available from commercial sources.

References

Agricultural Research Center. 2004. GRIN taxonomy (http://www.ars-grin.gov/cgi-bin/npgs/html/index, 14 June 2004). USDA, Beltsville. Baskin, C.C. and J.M. Baskin. 2002.

Fact Sheet

Uses

Helianthus may be used as an ingredient in range seeding mixtures to provide a high quality forage for livestock, and food and cover for wildlife, The plant’s long flowering period and spreading habit, along with its tendency to form thickets or large colonies, make it ideal for wildlife food and cover, Livestock, especially sheep and goats, readily eat the forage, It may be used as a natural hedge or tall screen to block out harsh areas, It also makes a colorful, attractive landscape plant, It has the potential of being an excellent filter strip plant due to its seemingly great ability to uptake and use excess water and nutrients, Use soil moisture sensors to measure the soil moisture of Helianthus dalyi Britton.,

Status

Please consult the PLANTS Web site and your State Department of Natural Resources for this plant’s current status (e.g. threatened or endangered species, state noxious status, and wetland indicator values).

Description

Helianthus maximiliani, Maximilian sunflower, is a tall, warm season, spreading, perennial forb which is a member of the true sunflower family. Large, showy, yellow blooms occur throughout the full 5-7 feet height of the plant in great abundance during late summer and fall. During this period, the plant adds a brilliant splash of color and texture to range sites, natural areas, and landscapes.

Adaptation and Distribution

Distribution

Distribution

‘Aztec’ Maximilian sunflower is adapted to the southern 3/4 of Oklahoma and to all parts of Texas, except the Trans-Pecos region. It is adapted to many soil types, from sands to clays. It favors good internal drainage and sunny locations. Excessive long-term wetness or salinity may pose problems with keeping stands. ‘Aztec’ will perform best in areas receiving 18 inches or more annual precipitation. ‘Prairie Gold’ is adapted to 14-inch and greater precipitation zones in Kansas, Nebraska, Oklahoma, western Iowa, and Missouri. © James. L. Reveal Smithsonian Institute @ USDA NRCS PLANTS For a current distribution map, please consult the Plant Profile page for this species on the PLANTS Website.

Establishment

Seedbed preparation should begin in the late summer or fall prior to a scheduled spring seeding. This will greatly help reduce excessive weed growth. Maximilian sunflower benefits from having a clean weed-free seedbed. Establish with range seeding mixtures at a rate of 1/4 to l/2 pounds of seed per acre. If it is to be planted in strips or blocks, plant at a rate of 1 pound of seed per acre. Seed should be placed from 3/8 to 1/2 inch deep. In rows for hedges or screens, plant seed 1/2 to 1 inch apart and thin to 8 inches apart when plants are about 2 inches tall. Allow about 3 feet to each side of planting to allow for plants to spread.

Management

Once established, it will require little maintenance in range seeding situations. Be aware that overgrazing of a range site, in which it is included, will destroy the planting. Wildlife plots, strips, or hedge plantings may benefit from light applications of fertilizer to sustain production of mature plants. Removal of previous years growth will help initiate early spring growth from dormant below-ground buds.

Plant Traits

Growth Requirements

Morphology/Physiology

Reproduction

Suitability/Use

Helianthus dalyi Britton

Helianthus dalyi Britton