Aster family (Asteraceae)
Description: This herbaceous biennial plant is a low-growing rosette during the 1st year. During the 2nd year, it sends up one or more flowering stems 1-3' tall. These stems branch sparingly above the withered remains of the rosette. Each stem is round, hairless, and often somewhat enlarged at the base of each leaf. The cauline leaves alternate sparingly and become smaller as they ascend the stems. They are up to 12" long and 1" across, lanceolate-linear in shape, smooth along the margins, and hairless. Their veins run parallel to each other, and at the base each leaf strongly clasps the stem. The basal leaves are similar to the cauline leaves in structure and appearance. Both the stems and leaves contain a white latex. Each stem terminates in a long naked stalk bearing a single flowerhead.
Each flowerhead is about 2" across when fully open, consisting of numerous yellow ray florets and about 8 green floral bracts that are lanceolate-linear in shape. The ray florets spread outward from the center of the flowerhead; the outer florets are noticeably longer than the inner florets. Each floret has a truncated tip with 5 small teeth. At its base, there is a columnar reproductive structure consisting of a yellow divided style and black anthers that are appressed together around the middle of the style. The floral bracts extend to about the outer margin of the flowerhead; sometimes, they are a little shorter or longer than the width of the flowerhead. The blooming period occurs from late spring to mid-summer and lasts about 1–1½ months. The flowerheads open up during the morning and close again by the afternoon. Each floret is replaced by an oblong achene that has a long thread-like beak, to which there is attached a tuft of hairs. These hairs are slightly plumose because they contain small hair-like branches. They are usually white at the base, but become dull brown toward their tips. Collectively, these achenes with their tufts of hair form a large spheroid ball that spans about 3–3½" across. Distribution of the achenes is provided by the wind. The root system consists of a fleshy taproot. This plant spreads by reseeding itself.
Cultivation: Typical growing conditions are full sun, average to above average levels of moisture, and a fertile loam or clay loam soil. In sterile soil, where this plant also occurs, it is usually smaller in size.
Range & Habitat: The adventive Yellow Goat's Beard is common in central and northern Illinois, but occasional or absent in the southern section of the state (see Distribution Map). It is native to Eurasia. Habitats include mesic black soil prairies, weedy meadows near woodlands, areas along roads and railroads, vacant lots, and miscellaneous waste areas. Disturbed areas are preferred, although this plant can be found occasionally in prairie remnants along railroads.
Faunal Associations: Various kinds of bees and flies visit the flowers for nectar or pollen. Occasionally, spittlebugs can be found where the leaves clasp the stem. The bitter white latex of the foliage deters the consumption of this plant by mammalian herbivores to some extent.
Photographic Location: A woodland meadow in Busey Woods at Urbana, Illinois. The flowerhead of one photograph is somewhat unusual for this species because the floral bracts extend beyond its outer margin and are clearly visible. In the other photograph, the foam of a spittlebug is evident at the base of one of the leaves.
Comments: Another common name for Yellow Goat's Beard is Meadow Salsify. It is closely related to Tragopogon porrifolius (The Oyster Plant), which is grown as a vegetable because of its edible roots. However, this latter species has purple flowerheads. Yellow Goat's Beard has an even closer resemblance to Tragopogon dubius (Western Goat's Beard), which is also common in the wild. While Yellow Goat's Beard has bright yellow flowerheads, Western Goat's Beard usually has pale yellow flowerheads. Yellow Goat's Beard has about 8 floral bracts that extend to the outer margin of the flowerhead (or slightly beyond in some cases), while Western Goat's Beard has about 13 floral bracts that extend considerably beyond the outer margin of the flowerhead. Also, the foliage of Western Goat's Beard has a tendency to be more pale green or blue-green in color. The foliage of Tragopogon spp. (Goat's Beards) resemble the foliage of Tradescantia spp. (Spiderworts), but these two groups of plants have very different flowers. Another difference is the absence of white latex in the foliage of Spiderworts.