![]() Leaves or bracts within the inflorescence subtend a single flower head or a fascicle that may produce a secondary flowering branch. Leaf/bract size and separation decreases toward the ends of branches. Branches have alternate leaves or bracts that are separated from each other by about ½ to 1/8 inch or less. The longest flowering branches tend to occur about mid-upper-stem with shorter braches below and above. The inflorescence, a series of composite flower heads along branches, occurs along and toward the ends of widely spreading and ascending, short to long branches. Bracts are especially numerous at the ends of the longest branches and secondary branches. The acicular leaves, which may be ½ inch long and 1/16 inch wide, further decrease in size to tiny acicular bracts. These leaves and bracts, also sessile, have the same color and pubescence as the larger leaves, though without winged bases. Leaves on branches that bear the inflorescence become smaller upwards, first becoming broadly acicular (needle-shaped), to acicular, then to bract-like. Lower along stem, axillary branches that bear flowers are shorter, as shown. Photo 3: In mid-October, pubescent stems are hard and brown. As plants mature in fall, especially with drying soils, lower leaves wither and drop off. The color on both sides of leaves is a similar medium green. Along with short ciliate hairs at leaf margins, similar scattered hairs occur on adaxial leaf surface while abaxial surface is more hairy with concentrations along primary veins and the leaf base. Slight up-folding occurs along midrib which is especially prominent along the winged base. Leaves have entire margins or small widely spaced serrations. Leaf width from mid-leaf to leaf base reduces down to narrow wings that continue to the sessile and clasping leaf base. The largest leaves, cauline leaves and those lower on branches, may be 4 inches long and ½ inch wide at mid-leaf and have a very gentle taper to leaf tips (acuminate). Leaves along stems (cauline leaves) and branches differ in size and shape from the basal leaves. Note pubescent stems, ciliate leaf margins, winged bases of stem leaves, and fascicles of leaves from leaf axils that will grow into branches. Photo 2: In mid-May, new stems may be 3 feet tall. The longer branches also produce fascicles that become secondary branches. Lower, down-stem, branches may be an inch or two long, while higher, up-stem, branches may reach 12 or even 16 inches. Leaves in these fascicles become alternate leaves along growing branches. Clusters of leaves (fascicles) arises from the leaf axils. Stem leaves are alternate, simple and spaced 1½ to 4 inches apart. Dead stems persist well into the next year, still exhibiting pubescence. The stout, straight stems tend to lean in various directions from the caudex. Pubescence of short hairs typically covers the entire stem. The largest stems may have splits in their epidermal layer due to lateral growth pressure. Mature plants have tall lanky stems that may reach 5 feet. Young stems are a medium green, but as the terete stems mature the color changes to brown or reddish brown and stems become hardened. White oldfield aster grows in clumps (cespitose) from a caudex and has both fibrous roots and rhizomes. Ciliate (marginal) hairs can be seen on new leaves. Photo 1: In November, stems are frozen and overwintering basal rosettes appear. The adaxial (upper) leaf surface is medium green, while the abaxial (lower) surface is a slightly lighter green. These leaves, which may be 3 inches long and an inch wide, have entire margins or a few widely spaced shallow serrations. Basal leaves are oval to elliptic with a narrowed base that may be glabrous or have scattered hairs on upper leaf surface as well as short marginal (ciliate) hairs. In late fall, after flowering, basal leaf rosettes appear and that persist over winter. Other common names include white heath aster, hairy aster, frost (based on dense hairs) aster, and awl (based on shape of phyllaries) aster. The specific epithet is from Latin for “hairy”. The genus name is from Greek for “junction” and “hair”, apparently based on a European cultivar. Habitats for this aster include old fields, open woodlands and roadways with a wide variety of dry to mesic soils. In Arkansas, this aster occurs statewide and is one of 22 species of aster ( Symphyotrichum) konwn to occur in the state. White oldfield aster ( Symphyotrichum pilosum), formerly Aster pilosus, a herbaceous perennial of the Aster (Asteraceae) family, occurs from Texas to South Dakota and Minnesota thence to the Atlantic and Gulf Coasts. ![]()
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