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Petradoria pumila - rock goldenrod

Scientific Family
Asteraceae
Synonyms
Aster pumilus, Chrysoma pumila, Solidago petradoria
Other common names
grassy rock goldenrod
Plant type
Forbs and Subshrubs
Origin
Native
Lifecycle
Perennial
Similar species
Petradoria pumila var. graminea, P. pumila var. pumila, Solidago graminea
Height
To about 10 inches
Riparian
No

Clump-forming plant often with many erect stems and narrow, green, grass-like leaves. It typically retains the previous year's dead leaves which surround the base of the plant. The flower stalk is a dense flat-topped cluster of small yellow flower heads.

Perennial; 1 to 20 slender erect sometimes rough feeling stems; leaves basal and on stems, gland-dotted, leathery, narrow, upper not stalked and reduced in size; ray flowers 1 to 3, disc flowers 30 to 40, both yellow; achenes topped with barbed bristles.

Habitat

Found on dry, sandy, rocky soils in flat open areas, on slopes, mesas, in canyons, in upland desert scrub, more common in pine and juniper woodlands as well as along hiking trails, roads and meadows.

Plant Community
Desert Scrub
Disturbed Areas
Grasslands
Interior Chaparral
Montane Conifer Forest
Pinyon Juniper Woodlands
Low elevation
4500
High elevation
7500

Flower Characteristics

Flower stalk has flat-topped compact clusters of yellow flower heads, each up to 1/8 inch wide. Vertical whorls of yellow to brownish leaf-like bracts with darker tips, each up to 1/4 inch long, are closely pressed into the stem beneath the flower head.

Flower color
Yellow
Flower shape
Daisy or dandelion-like
Tubular
No
First bloom month
June
Last bloom month
September
Flower clusters
Rounded

Leaf and Stem Characteristics

Leaves are leathery, 3/4 to 4-3/4 inches long, 1/16 to 1/2 inch wide, dotted with tiny oil glands and often have 3 veins but may have 5. The leaves, leaf margins and stem surfaces are coarse. Basal leaves have short stalks, stem leaves are stalkless.

Leaf type
Simple
Leaf color
Green
Leaf shape
Narrow
Leaf margin
Smooth
Leaf attachment
Basal & Alternate
Leaves clasp
No
Leaf hairs
None
Spines
No

Fruit and Seed Characteristics

Fruit is dry, 1-seeded, smooth, about 1/4 inch long with 6 to 9 veins. At its top are 30 to 60 tan minutely barbed hair-like bristles (pappi) each about 1/8 to 1/4 inch long. When mature, fruit does not split open to release the seed.

Fruit type
Achene

The seed is smooth and has a hard outer shell. The surface of the seed is not attached to the wall of the fruit making it easier to disperse when mature. The numerous barbed bristles at the top of the fruit also aid in seed dispersal by wind or animals.