Maximilian_Sunflower

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(updated May 17, 2021)

Maximilian Sunflower

Helianthus maximiliani Schrad.

Asteraceae (Sunflower Family)

▲▼ mature, flowering plants

▲▼head inflorescences

▲▼stems and leaves

Helianthus maximiliani Schrad., Maximilian Sunflower: (Bayer Code: HELMA; US Code HEMN2)

· U.S. native creeping perennial, rhizome-producing wildflower that grows 1.5-10 feet tall or more, usually with unbranched, green rough-textured, hairy stems

· Leaves are mostly alternate, lanceolate, up to 12 inches long, light-green usually with smooth margins and a pointed tip, although sometimes leaves have a few teeth along the margins; leaves have very short or no petioles; both surfaces of the leaf are covered with fine, white hairs; upper surface has is dotted with glands; leaf margins tend to fold up along the midvein, and the whole leaf curves downward from the stem toward the leaf tip

· Head inflorescences are 2-3.5 inches in diameter, produced at stem tips, with 10-25 yellow ray florets (“petals”) that are puckered or ridged where they join the head, and 75 or more yellow disk florets

· Bracts below the head are in overlapping rows, linear-lanceolate, with very long, tapering, pointed tips; bract tips curve out from base of head, are hairy with some gland dots

· Flowering from late summer through autumn

· Prefers full-sun, pastures, prairies, rangeland, glades, right-of-ways

· The green, rough-textured, hairy stems and very long, thin leaves covered with white hairs are characteristic for this species of perennial sunflower; similar Sawtooth Sunflower (Helianthus grosserratus) has reddish-green to purplish, hairless stems with a waxy bloom/coating

PERENNIAL SUNFLOWERS:

· Include Ashy Sunflower, Texas Blueweed, Maximilian Sunflower, Sawtooth Sunflower, Western Sunflower, Willowleaf Sunflower, Jerusalem Artichoke, and other species

· All are creeping perennial weeds that form rhizomes and/or creeping roots that allow them to spread to form colonies with maturity

· Most are palatable to livestock, except in fertile soils, where high nitrate accumulation may cause poisoning, but may be seen as weedy in reduced tillage crops

· Once established, these species can be hard to control, but most (not all) are not considered to be weedy

· Most produce relatively tall (4-8 feet tall or more), unbranched, leafy stems with linear, lanceolate to ovate/triangular, rough-textured leaves; upper stem portions are usually branched with the onset of flowering, so that each branch stem tip has a flower head

· Flowers for most perennial sunflowers quite similar (with some exceptions); they are in terminal clusters, flowering usually sometime from mid-summer to late autumn, with yellow ray flowers and yellow to brown disk flowers; total flower diameter is usually 2-4 inches

o Perennial sunflower “flowers” are usually smaller than annual sunflower “flowers,” such as with Annual Sunflower (Helianthus annuus) or Prairie Sunflower (Helianthus petiolaris)

· Usually, it is more of the stem and leaf characteristics that are used to identify the different perennial sunflower species

· Click on links of above individual plant names to see more information on each one

· Most perennial sunflowers are native plants that usually do not cause harm in grazing or haying situations (maybe with the exception of Texas blueweed). Perennial sunflowers provide food and nectar for native insects (including bees and butterflies), birds and other animals, and generally should not be killed indiscriminately. Maintaining proper grazing levels can often reduce their unwanted increase in pastures and rangeland.

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