Asters (16)
Asters are distinguished from daisies by their bracts, which circle the under-side of the flower. Most asters have bracts that overlap, like shingles. Daisies have bracts about the same length, like a fence. Asters bloom later in the summer than daisies. There are many asters. Their location, elevation, bracts and leaves differentiate them but it is still difficult to accurately identify them. See also White Asters.
Alkali Marsh Aster
Almutaster pauciflorus
Family:
Sunflower (Asteraceae)
AKA:
Marsh Alkali Aster, Few-flowered Aster
Photo taken on:
September 7, 2013
Location:
Rio Chama, Abiquiu, NM
Life Zones:
Plains and foothills
Habitat:
Moist alkaline soil, river sides, ditches
Grows to 2 feet with sparse narrow leaves. Flowers are ¾" across, very pale lavender and grow in a loose, branching cluster. Bracts are narrow and green.
Flora of North America reference.
Small-flower Tansyaster
Arida parviflora (Machaeranthera parviflora)
Family:
Sunflower (Asteraceae)
AKA:
Photo taken on:
September 24, 2015
Location:
CR 155, Abiquiu, NM
Life Zones:
Plains and foothills
Habitat:
Sandy areas,
roadsides, river margins, saline soils
Grows to less than 2 feet with many branched, wiry stems. Leaves are no more than 1" long, are deeply divided and clasp the stem. They do not have a spiny tip like Tanseyleaf Tansyaster. Bracts are in 3-4 rows, are greenish and spreading. Flower heads are about ¾" across. Petals curl after flowering.
Flora of North America reference.
Fall Tansyaster
Dieteria asteroides var. asteroides
Family:
Sunflower (Asteraceae)
AKA:
New Mexico Tansyaster, Starry Spine Aster
Photo taken on:
October 18, 2014
Location:
Abiquiu, NM
Life Zones:
Plains and foothills
Habitat:
Dry areas, roadsides
Fall Tansyaster is very similar to the Hoary Tansyaster and
Bigelow's Tansyaster. In Abiquiu they bloomed in the middle of October after the Hoary Aster had
gone to seed and succumbed to the first frost (in the background). They
were less than 2ft high with a single stem branched at the top and not
as widely branched as Hoary Tansyaster. 
The leaves at mid-stem are narrow and saw-toothed. The bracts are long, hairy and curve backwards.
Flora of North America reference.
Bigelow's Tansyaster
Dieteria bigelovii (Machaeranthera bigelovii)
Family:
Sunflower (Asteraceae)
AKA:
Tall Tansy Aster, Sticky Aster, Bigelow's
Spine
Aster
Photo taken on:
September 7, 2007
Location:
Almont, CO
Life Zones:
Foothills to subalpine
Habitat:
Disturbed areas, roadsides
Grows to 5 feet tall. Flowers are more violet blue than Hoary Tansyaster. Bracts and upper stem are sticky and longer. Leaves are more lance-shaped and wider.
Flora of North America reference.
Hoary Tansyaster
Dieteria canescens (Machaeranthera canescens)
Family:
Sunflower (Asteraceae)
AKA:
Hoary Aster, Purple Tansy Aster
Photo taken on:
August 18, 2007
Location:
Walrod Gulch, GV, CO
Life Zones:
Foothills to montane
Habitat:
Dry areas, roadsides
There are a lot of similarities between Hoary Tansyaster and Bigelow's Tansyaster. Both grow with spreading branches. This grows to 3 feet tall. Bracts are curved out but not as long as Bigelow's. Leaves are narrow. It grows at lower elevations.
Photos taken on:
September 15, 2014
Location:
Abiquiu, NM
Hoary Tansyasters can cover a vast area, as shown below. These photos show lighter violet and white flower heads.
Flora of North America reference.
Gray Aster
Herrickia glauca var. glauca
(Eurybia glauca, Aster glaucodes, et.
al.)
Family:
Sunflower (Asteraceae)
AKA:
Photo taken on:
July 28, 2004
Location:
Almont, CO
Life Zones:
Plains to foothills
Habitat:
Moist areas, woodlands
Grows to over 2 feet in colonies with gray-green, leaves
that have smooth edges and can be from ¼" to 1" wide and 4 ½" long.
Plants can have up 100 flower heads.
Photo taken on:
August 5, 2007
Location:
Cement Creek, GV, CO
Flowers are pale purple with 10-19 rays and yellow centers which turn purplish. Outer bracts are rounded and green, inner bracts are pointed and purplish.
Similar to Smooth Aster but the bracts differentiate.
Flora of North America reference.
Tanseyleaf Tansyaster
Machaeranthera tanacetifolia
Family:
Sunflower (Asteraceae)
AKA:
Tahoka Daisy, Tanseyleaf Spine Aster
Photo taken on: August 18, 2014
Location:
Ghost Ranch, Abiquiu, NM
Life Zones:
Plains and foothills
Habitat:
Sandy, rocky, disturbed areas,
pinyon-juniper
Grows less than 2 feet tall. It is also differentiated from the other Tansyasters by the leaves which are pinnately divided with toothed lobes and spiny tips. The purple flower has white at the base of the petals.
Flora of North America reference.
Western Aster
Symphyotrichum ascendens (Aster ascendens)
Family:
Sunflower (Asteraceae)
AKA:
Common Aster, Long-leaved Aster
Photo taken on:
August 16, 2004
Location:
Almont, CO
Life Zones:
Foothills to subalpine
Habitat:
Meadows, roadsides
Grows to 30" in colonies with multiple flower heads
and rough, wiry stems. Basal leaves are lance-shaped, withering as plant blooms; stem leaves
are narrow and clasping. Pale violet flowers are 1" across with green and white bracts.
Flora of North America reference.
Cluster Aster
Symphyotrichum falcatum (Aster falcatus)
Family:
Sunflower (Asteraceae)
AKA:
White Prairie Aster, Sickle Aster
Photo taken on:
July 25, 2007
Location:
Almont, CO
Life Zones:
Foothills to montane
Habitat:
Meadows, roadsides
Grows to 2 feet in patches with 1" wide white or pale blue flowers and long, soft, green leaves. Bracts are pale with green tips and curve outwards.
Flora of North America reference.
Sunloving Aster
Symphyotrichum foliaceum var. apricum
(Aster foliaceus var. apricus)
Family:
Sunflower (Asteraceae)
AKA:
Leafy Aster, Alpine Leafybract Aster
Photo taken on:
August 12, 2007
Location:
Daisy Pass Trail, GV, CO
Life Zones:
Subalpine to alpine
Habitat:
Open areas
Grows to 8" with reddish hairy stems. Flowers are about 1" across, usually purple and borne singly, with large, leafy, purple-tipped bracts. Leaves are smooth and clasping.
Leafy Aster
Symphyotrichum foliaceum var. canbyi (Aster foliaceus)
Family:
Sunflower (Asteraceae)
AKA:
Canby's Aster
Photo taken on:
August 11, 2007
Location:
Rustler Gulch, GV, CO
Life Zones:
Foothills to subalpine
Habitat:
Meadows, moist, open places
Grows from 3" to 24" in clumps with 1½" flowers and large leafy bracts. Leaves are broad and long and clasp the stems. Flowers can be white.
According to Flora of North America "Symphyotrichum foliaceum is extremely variable and is widespread in western montane coniferous forests and subalpine meadows" which is where I found all of them.
Leafy Aster
Symphyotrichum foliaceum var. parryi
(Aster foliaceus var. parryi)
Family:
Sunflower (Asteraceae)
AKA:
Parry's Aster
Photo taken on:
August 12, 2007
Location:
Daisy Pass Trail, GV, CO
Life Zones:
Foothills to subalpine
Habitat: Moist areas
Grows to 12". Flowers stems are branched. Flowers are showy, about 1½" across, and range from violet, blue to rose-purple with unequal, oblong bracts.
Smooth Aster
Symphyotrichum laeve var. geyeri (Aster geyeri)
Family:
Sunflower (Asteraceae)
AKA:
Smooth Blue Aster, Geyer's Aster
Photo taken on:
September 1, 2013
Location:
Wet Mountains, Eastern CO
Life Zones:
Plains to montane
Habitat:
Dry meadows, open forests
Grows to 2 ½ feet with a stout, smooth stem and thick, firm, green or bluish-green leaves. Upper leaves clasp the stems. Leaves and stems are hairless. Clusters of 1" wide flowers grow in branches in the upper half with yellow centers turning purplish. Bracts are whitish with green tips.
Flora of North America reference.
Panicled Aster
Symphyotrichum lanceolatum var. hesperium (Aster hesperius)
Family:
Sunflower (Asteraceae)
AKA:
Lance-leaved Aster, White Panicle Aster, Willow Aster
Photo below taken on:
September 28, 2015
Location:
Abiquiu, NM
Life Zones:
Plains, foothills and montane
Habitat:
Moist soils, meadows, ditches, stream
banks
Grows to 3 feet with narrow, lance-shaped leaves, up to 4" long. Withered leaves remain on the stem and curl. Flowers are about ¾" across and grow in loose, leafy clusters and can be white to pale lavender with yellow centers that turn reddish with age. Bracts are narrow, green and pale at the base.
Flora of North America reference.
Aromatic Aster
Symphyotrichum oblongifolium (Aster oblongifolius)
Family:
Sunflower (Asteraceae)
AKA:
Oblong-leaved Aster
Photo taken on:
September 2, 2013
Location:
Wet Mountains, Eastern CO
Life Zones:
Plains and foothills
Habitat:
Dry, open slopes, prairies
Grows with a bushy habit to 18". Leaves are oblong-shaped. At bloom time lower leaves are withered and upper leaves decrease in size to become spreading bracts. Flowers are 1" across or more with yellow flower disks that age to red. The foliage gives a pleasant odor when crushed. This aster is distinguished by its aroma, the spreading narrow bracts and its bushy habit compared to the taller, lanky asters.
Flora of North America reference.
Western Mountain Aster
Symphyotrichum spathulatum var. spathulatum
(Aster occidentalis var. occidentalis)
Family:
Sunflower (Asteraceae)
AKA:
Mountain American Aster
Photo taken on:
August 17, 2021
Location:
Roaring Judy Fish Hatchery, GV, CO
Life Zones:
Foothills to subalpine
Habitat:
Moist
meadows, aspen & conifer forests
Grows to 18" in colonies with few branches of 3 to 10 flower heads and smooth, lance-shaped basal and stem leaves. The bracts are pointed and green and uneven in length. A variable and widespread species says the FNA.
Flora of North America reference.