Southern Jimmy Weed or Rayless Goldenrod is an erect, dense, herbaceous perennial shrub in the daisy family native to the America southwest. It is a flowering plant with a long season stretching from April to October. The plant is often found in salty, dry or rocky soil, sometimes over gypsum, and sandy or clay loam. This shrub is usually woody toward the base with erect, branching stems topped with numerous yellow flowers that form dense terminal cymes. The genus name is from Greek iso- for equal and coma, or hair of the head, referring to the flat-topped inflorences. The species name means many-flowered. Southern Jimmy Weed can be a weed in roadsides near irrigated areas or in overgrazed pastures and is poisonous to livestock, causing "trembles", which can be passed through the milk to humans. The toxic compound is present in both green and dry material. Diseases, Insect Pests, and Other Plant Problems: No known diseases or insect pests. Toxic to livestock.
Curated pairwise relationships between this plant and others in the library — who feeds
whom, who competes, who confuses the pests. Green reads as a good pairing, red as one to avoid.
No curated interactions recorded for this species yet.
Also noted by NC State
Related species the NC State Plant Toolbox flags for this plant — look-alikes to tell
apart, and plants that play a similar role in a planting. Ones we carry in the library are linked.
Full sun (6 or more hours of direct sunlight a day)
Soil texture
Clay; Loam (Silt); Sand; Shallow Rocky
Soil drainage
Moist
Mature size
Height: 3 ft. 0 in. - 5 ft. 0 in. | Width: 1 ft. 0 in. - 1 ft. 6 in.
Maintenance
Low
Canopy layer
3 - Shrub (3-15 ft)
Form & Appearance
Habit / form
Arching; Dense; Erect
Leaf color
Gray/Silver; Green
Leaf type
Simple
Leaf arrangement
Alternate
Leaf shape
Linear; Oblanceolate
Leaf margin
Dentate; Entire
Leaf size
1-3 inches long, < 1 inch wide
Hairs present
No
Leaf detail
Gray green leaves are simple, alternate along the stems, linear and sticky. The margins entire to sparsely short-dentate. Leaves are 3/4 of an inch to 1 1/2 inches long and 1/8 of an inch wide.
Flower color
Gold/Yellow
Flower value
Long Bloom Season
Flower form
Cyme
Flower shape
Radial
Flower size
< 1 inch
Flower detail
Numerous flower heads of small blossoms form dense terminal cymes, straw colored with yellowish or greenish tips, 7-15 florets per flower head.
Bloom time
Fall; Spring; Summer
Fruit detail
The fruit is a cypsela, although it is often referred to as an achene.
Wildlife & Ecology
Native status
Native
Origin
Southwestern United States and Mexico
Distribution
Texas, Arizona, Colorado, New Mexico
Landscape Use
Garden tags
#problem for horses #herbaceous perennial #flowering shrub #shrub #yellow flowers #problem for cattle