Al Schneider's Rocky Mountains Plant Descriptions

Tall Western Groundsel
Senecio integerrimus
Aster family (Asteraceae)

Senecio is a large with several dozen species occurring in the Colorado Rockies region. This species is common in and wetlands and also prospers in dry Oak and Spruce forests and Sagebrush. Arrow-leaved Groundsel (S. triangularis), distinguished by its large triangular leaves, prefers higher elevations and more moist soils than Tall Western Groundsel.

Thomas Nuttall collected the first specimens of this plant for science in 1811 on the plains near the Missouri River in what is now Montana. "Integerrimus" is from the Latin for ", whole, or complete" perhaps referring to the "" (smooth-edged) leaves or to the compact cluster of flowers. "Senecio" is from the Latin, "senes," "old man," and refers to the hairs, the white, tiny, hair-like growth at the of the seeds in Asteraceae.


©2011 Matt Lavin

Description

Stout, erect , 8-27" tall, with numerous yellow flowerheads in a cluster. Flowerheads have narrow yellow rays and black-tipped, hairy . The central head is often larger with thicker . , spoon-shaped and . Leaves somewhat fleshy, stiff-hairy, to irregularly and twice as long as wide. Stem leaves few, -, growing smaller upwards on the . Stems are erect, single, cobwebby-hairy to hairless, especially with age.

Field Marks

Yellow rounded flowerheads with black-tipped ; leaves.

© Al Schneider

An entire leaf has smooth edges. Not toothed or lobed.

A perennial plant lives and blooms for many years.

The apex is the tip or the furthest point from the attachment.

A herb is a plant whose stems die back to the ground in the winter.

subalpine -- Just below the timberline.

basal leaves -- a leaf that grows lowest on the stem of a plant.

Bracts are modified leaves associated with a flower.

pappus -- Small scales, bristles or hairs at the top of the seed in Asteraceae. For example, dandelion parachutes. Plural: pappi.

terminal -- Located at the end (the tip or the apex).

Like the teeth on a saw, leaves and other surfaces can have toothed edges.

stalk -- The supporting structure of an organ. Examples of stalks are stem, peduncle, petiole, ...

montane -- inhabiting mountainous country but below timberline.

genus -- A subdivision of a botanical Family in which all members have a significant number of similar characteristics.

alternate -- leaves alternate along the main stem and are attached singly.

lanceolate -- Lance-shaped. Long, wider in the middle.

linear -- Long and very narrow like a blade of grass.