Montana Field Guide

PLANTS: Perennial plants that grow from a taproot. Stems decumbent to erect, woody at the base, and 10–50 cm tall. Hairs are strigose (stiff, straight, sharp, and appressed) to hirsute (long and stiff), often stipitate-glandular (stalked glands). Source: Lesica et al. 2012

LEAVES: Alternately arranged on the stem (cauline). Those on the lower stem petiolate and upwards becoming sessile. Leaf blades are oblanceolate to obovate in shape with smooth (entire) margins, and 1–5 cm long. Source: Lesica et al. 2012

INFLORESCENCE: Yellow flowers in heads arranged in leafy-bracted corymbiform arrays. Flower stems (peduncles) are 0–3 cm long. Involucre is narrowly campanulate, 5–10 mm high. Involucral bracts (phyllaries) are imbricate forming 4 to 5 rows; bracts are green, narrowly lanceolate, white-margined, and glabrate to strigose, though sometimes glandular. The receptacle is nearly flat. Heads composed of yellow ray and disk florets (radiate). Fruit is a Cypsela, a specific type of achene. Source: Lesica et al. 2012

VARIETY villosa: Stems and leaves densely hirsute and lacking glands. Leaves are more oblanceolate in shape. Flower Heads on longer peduncles and subtended by small bracts. Source: Lesica et al. 2012

Heterotheca is derived from the Greek words heteros meaning 'different' and thece meaning 'container' which refers to ray and disk cypsela being morphological different in some species (dimorphic cypsela) (Semple in Flora of North America [FNA] 2006).

Heterotheca villosa has 5 varieties in Montana (Semple in FNA 2006), of which 3 varieties are recognized in the Manual of Montana Vascular Plants (Lesica et al. 2012):

Variety villosa
Flora of North America
*Stems: 16-39 cm tall and moderately to densely strigose and sparsely to abundantly long-hirsute.
*Upper Leaves are moderately strigose (20-60 hairs per square millimeter) and sparsely to moderately stipitate-glandular.
*Flower Heads: Usually lack bracts on the peduncles.
*Distribution: Great Plains and scattered in hills and mountains.
Manual of Montana Vascular Plants
*Stems and upper leaves densely hirsute and lacking glands.
*Flower heads on longer peduncles and subtended by small bracts.
*Leaves are more oblanceolate in shape.
*Found mostly on the plains in Montana.

Variety foliosa
Flora of North America
*Stems: 5-22 cm tall and usually abundantly long-hirsute.
*Flower Heads: Narrowly campanulate involucre. Less showy ray florets, (7)13-22 in number, 8-11.4(12.4) mm in length.
*Distribution: Mountains and western prairies.
Manual of Montana Vascular Plants
*Stems and upper leaves densely hirsute and lacking glands.
*Flower heads on very short peduncles and immediately subtended by leaves.
*Leaves are oblong to obovate in shape.
*Found mostly along streams on the plains in Montana.

Variety minor
Flora of North America
*Overall: Upper leaves are narrowly to broadly oblanceolate (sometimes oblong or ovate in the mountains), moderately glandular (4-20 glands per square millimeter), and hispido-strigose (10-50 hairs per square millimeter). Upper leaf bases are cuneate or attenuate, but rarely rounded.
*Stems: decumbent to ascending-erect, (9)16-33(48) cm tall. Branches usually not very long.
*Upper Leaves: Margins flat to undulate with obtuse to acute leaf tips, and sparse to moderate hairs.
*Flower Heads: Arrays are compact. Involucral bracts are moderately strigose (hairs to 1 mm long) and usually stipitate-glandular.
*Distribution: Throughout most of the range described for the species.
Manual of Montana Vascular Plants
*Stems sparsely to densely stipitate-glandular, but not densely hirsute.
*Found in plains, valleys, to rarely the subalpine in Montana.
*Montana's most common form.

Variety depressa
Flora of North America
*Overall: Small stature, small flower heads, and linear-oblanceolate leaves with many hairs and usually some glands.
*Stems: 5-22 cm tall and sparsely long-hirsute.
*Upper Leaves are densely strigose (84-140 hairs per square millimeter) and sparsely to moderately stipitate-glandular.
*Distribution: Yellowstone National Park and adjacent areas.

Variety ballardii
Flora of North America
*Overall: Plants have leaves with round bases, short hairs, and not glandular and flower heads that are large, many-rayed and often subtended by one or more large, narrow, leaf-like peduncle bracts.
*Stems: 22-50 cm tall and usually abundantly long-hirsute.
*Flower Heads: Broadly campanulate involucre. Showy ray florets, (12)17-20 in number, (8.5)9-14.5 mm in length.
*Distribution: Northeastern Great Plains.

Found mostly on the plains in Montana (Lesica et al. 2012).