This is a truly beautiful little plant with attractive foliage and flowers. It's an excellent candidate as a wildflower in a rock garden. Silky Aster can be distinguished from all other asters by its exceptional foliage, which has a silvery or silky appearance because of the numerous fine hairs covering the stems and foliage.

This native perennial plant is 1-2' tall, often sprawling along the ground. The wiry stems branch occasionally, and have a tendency to zigzag between the leaves. They are whitish green or silver and covered with a fine pubescence when young, becoming brown and bare when old. The alternate leaves are silvery green and have a silky appearance as the result of a dense coating of fine hairs. They are about 1½" long and ½" wide, lanceolate or ovate, and sessile. Their margins are smooth. The daisy-like composite flowers occur in small clusters at the terminus of major stems. They are about 1¼" across, consisting of 12-25 ray florets that are lavender to violet-blue, and numerous central disk florets that are golden yellow. There is no noticeable floral scent. The blooming period occurs during the fall and lasts about a month. The achenes develop small tufts of hairs, and are dispersed by the wind. The root system forms a short caudex on mature plants and some fibrous roots. Occasionally, vegetative offsets are formed.

Aster sericeus Vent.:
Canada (North America)
United States (North America)

Canada

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

United States

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

Silky Aster occurs primarily in the northern tier of counties, and in many counties along the Illinois and Mississippi Rivers. It is an uncommon plant that appears to be declining in numbers as a result of habitat destruction. Habitats include dry gravel prairies, dolomite prairies, sand prairies, hill prairies, scrubby barrens, limestone glades, and prairie remnants along railroads (rarely). This is an indicator plant of high quality habitats in dry areas.

Symphyotrichum sericeum is known in the Bahamas as S. lucayanum (Britton) G. L. Nesom [syn. Aster lucayanus Britton, Virgulus lucayanus (Britton) Reveal & Keener]. It is of conservation concern in Indiana, Michigan, and Canada. Symphyotrichum sericeum is distinct and unlikely to be confused with other species due to its silvery-silky leaves and phyllaries, open arrays, and cormoid rootstocks. Aster sericeus forma albiligulatus Fassett is a white form of the species, in contrast to the typically purple forma sericeus; these do not deserve formal recognition.

Perennials, (20–)30–70 cm, cespitose, eglandular; with short, woody, cormoid caudices, or short rhizomes. Stems 1–5+, ascending to erect (thin, grayish brown to dark brown), glabrous proximally, densely canescent distally. Leaves (silvery) firm, soft; basal withering by flowering, sessile, blades (1–3 nerved) elliptic-lanceolate, 10–40 × 5–15 mm, bases cuneate, weakly sheathing, margins usually entire, rarely remotely serrate, piloso-ciliate, apices acute, faces less copiously hairy than cauline; proximal cauline withering by flowering, sessile, blades oblanceolate or oblong to linear-lanceolate, 15–30(–50) × 4–10 mm, slightly and progressively reduced distally, bases rounded, sub­clasping, margins entire, silky-pilose, apices obtuse to acute, mucronulate, faces sparsely to densely silky-pilose; distal sessile, blades lanceolate, 10–30 × 5–8 mm, little reduced distally, bases cuneate, margins entire, apices acute, mucronate, faces ± densely silky. Heads in open, paniculiform arrays, branches sparse, fastigiate, often arching (1–5+ per branch). Peduncles subsessile or 0.5–3(–5) cm, densely sericeo-strigose, bracts crowded, 4–8(–10) mm, grading into phyllaries. Involucres campanulate to cylindric, (5–)7.5–10 mm. Phyllaries in 3–5(–6) series, outer ovate with expanded distal portion [(4–)5–6 mm], mid ovate-lanceolate [6–8(–10) mm] with expanded green portions, inner linear, unequal or sometimes subequal, outer often foliaceous, bases (mid) scarious, margins silky, green zones restricted to expanded distal ¹ / 2 – ² / 3 (obscured by hairs), apices (outer) spreading or squarrose to reflexed, acute, mucronulate, faces densely long-silky. Ray florets (10–)15–30; corollas usually rose-purple to deep purple, rarely white, laminae 8.5–11 × 1–1.5 mm. Disc florets (15–)25–35; corollas pink turning purple, (5–)5.5–7 mm, tubes shorter than narrowly funnelform throats (both thinly puberulent), lobes deltate, 0.7–0.9 mm. Cypselae purple or brown, obovoid, not compressed, 2–3 mm, 7–10-nerved (prominent), faces glabrous; pappi whitish or tawny, 6–7 mm. 2n = 10, 20.

Aster sericeus Ventenat, Descr. Pl. Nouv., plate 33. 1800; Lasallea sericea (Ventenat) Greene; Virgulus sericeus (Ventenat) Reveal & Keener

Silky Aster occurs primarily in the northern tier of counties, and in many counties along the Illinois and Mississippi Rivers. It is an uncommon plant that appears to be declining in numbers as a result of habitat destruction. Habitats include dry gravel prairies, dolomite prairies, sand prairies, hill prairies, scrubby barrens, limestone glades, and prairie remnants along railroads (rarely). This is an indicator plant of high quality habitats in dry areas.

Aster sericeus (Silky Aster)
(Bees suck nectar or collect pollen, flies suck nectar or feed on pollen, other insects suck nectar; observations are from Reed)

Bees (long-tongued)
Apidae (Bombini): Bombus affinis, Bombus impatiens, Bombus vagans; Anthophoridae (Eucerini): Melissodes dentiventris; Megachilidae (Coelioxini): Coelioxys rufitarsis; Megachilidae (Megachilini): Megachile latimanus, Megachile relativa

Bees (short-tongued)
Halictidae (Halictinae): Agapostemon sericea, Agapostemon texanus texanus, Lasioglossum leucozonia

Wasps
Ichneumonidae: Exetastes angustoralis

Flies
Syrphidae: Eristalis dimidiatus, Eristalis stipator, Helophilus latifrons, Helophilus stipatus, Syrphus sp.; Bombyliidae: Systoechus sp.

Butterflies
Pieridae: Colias sp.

Little information is available for this plant. Like other asters, many kinds of insects probably visit the flowers, especially bees, and to a lesser extent small butterflies, skippers, and Syrphid flies. Among the bees, Green Metallic bees are freqent visitors. The Syrphid flies probably feed on pollen and are non-pollinating. Mammalian herbivores eat this plant readily, especially rabbits and groundhogs. Its small size may partially exempt this plant from the attention of large herbivores, such as deer.

Canada

Rounded National Status Rank: N2 - Imperiled

United States

Rounded National Status Rank: N5 - Secure

Rounded Global Status Rank: G5 - Secure

Reasons: Widespread from Texas through the midwestern United States north to Canada (Kartesz 1999). Symphyotrichum sericeum is found in prairies, fields, and open rocky calcareous soils (Correll and Johnston 1970, Van Bruggen 1976, Voss 1996). It is frequent in the Great Plains of the United States and only becomes rare in the northern and eastern portion of its range.

The preference is full sun and dry conditions. Almost any kind of soil is satifactory if the site is well-drained, but this plant typically grows in poor soil that is rocky or sandy. A high pH is tolerated. Overall, this plant develops more slowly than most and is a bit more difficult to grow. It doesn't like too much competition from taller, more aggressive plants. The drought tolerance of mature plants is excellent, although some of the lower leaves will drop from their stems. Foliar disease doesn't seem to bother it.

Comments: Excludes plants sometimes known as Aster sericeus var. microphyllus; these are considered as a distinct species, Symphyotrichum pratense.