Category: Asteraceae

  • Hollow Joe-Pye-Weed (Eupatorium fistulosum)

    Probably the most common species of Joe-Pye-Weed in our area. Most botanists today put Joe-Pye-Weeds in the genus Eutrochium; we keep the name Eupatorium for the convenience of Internet searchers.

    This magnificent plant, with its domes of dusty-rose flowers on towering stems, is common in damp fields and roadsides everywhere; these plants grew in a moist depression in Schenley Park, side by side with their close cousins the Spotted Joe-Pye-Weeds (E. maculatum). Enlightened gardeners who have space for a few eight-foot towers in their perennial beds are beginning to discover and make use of this plant, which can now be seen in some of Pittsburgh’s most tasteful gardens.

    The taxonomy of the Joe-Pye-Weeds seems to be in an awful mess. Alphonso Wood’s Class-Book of Botany seems to be closest to the modern botanists’ classification of this species, so we use Wood’s description here:

    EUPATORIUM.

    Dedicated to Eupator, king of Pontus, who first used the plant m medicine.

    Flowers all tubular; involucre imbricate, oblong; style much exserted, deeply cleft; anthers included; receptacle naked, flat ; pappus simple, scabrous; achenia 5-angled.—Perennial herbs, with opposite or verticillate leaves. Heads corymbose. Flowers of the cyanic series, that is, white, blue, red, &c., never yellow.

    Leaves verticillate. Flowers purple.

    E. fistulosum Barratt. (E. purpureum Willd. in part. E. incarnatum Linn., in part. E. purpureum, v. angustifolium T. & G.) Trumpet-weed.Stem fistulous, glabrous, glaucous-purple, striate or fluted; leaves in about 12 whorls of 6s, largest in the middle of the stem, rather finely glandular-serrate; midvein and veinlets livid purple; corymb globose, with whorled peduncles.—Thickets, U. S. and Can., very abundant in the Western States! Height 6-10 ft., hollow its whole length. Leaves, including the 1″ petiole, 8 by 2″. Corymb often 1 ft. diam. Flowers purple. The glaucous hue and suffused redness of this majestic plant are most conspicuous in flowering-time. It does not appear to possess the acrid properties of E. maculatum. July—Sept.

  • Fleabane (Erigeron strigosus)

    Also called “Daisy Fleabane,” “Fleabane Daisy,” “Plains Fleabane,” “Prairie Fleabane,” and probably many other names. Pittsburghers usually call them “little daisies.” Old herbal legend has it that dried plants repel fleas. Fleabane is very common around here; if it were not, it would be treasured as a garden ornamental. It blooms for a good bit of the summer; these were blooming in late June in a clearing in the woods in Scott Township.

    The seventh edition of Gray lists this as Erigeron ramosus, though the sixth had listed it as E. strigosus.

    ERIGERON L. FLEABANE. Heads many-flowered, radiate, mostly flat or hemispherical; the narrow rays very numerous, pistillate. Involucral bracts narrow, equal, and little imbricated, never coriaceous, neither foliaceous nor green-tipped. Receptacle flat or convex, naked. Achenes flattened, usually pubescent and 2-nerved; pappus a single row of capillary bristles, with minuter ones intermixed, or with a distinct short outer pappus of little bristles or chaffy scales. Herbs, with entire or toothed and generally sessile leaves, and solitary or corymbed naked-pedunculate heads. Disk yellow; rays white, pink, or purple. (The ancient name presumably of a Senecio, from er, spring, and geron, an old man, suggested by the hoariness of some vernal species.)

    E. ramosus (Walt.) BSP. (DAISY F.) Stem panicled-corymbose at the summit, roughish like the leaves with minute appressed hairs, or almost smooth; leaves entire or nearly so, the upper lanceolate, scattered, the lowest oblong or spatulate, tapering into a slender petiole; rays white, twice the length of the minutely hairy involucre. (E. strigosus Muhl.) Fields, etc., common. June-Oct. Stem smaller and more simple than the preceding [E. annuus], with smaller heads but longer rays. Var. DISCOIDEUS (Robbins) BSP., with the rays minute, scarcely exceeding the involucre, occurs in s. N. E. and N. Y.

  • Coltsfoot (Tussilago farfara)

    Coltsfoot is one of our earlier spring flowers; these were blooming on the grounds of the Pittsburgh Zoo, Highland Park, in early April. The cheery and shaggy yellow flower heads top a short stalk that pops straight out of the ground; there are no leaves until later on. The plant’s favorite habitat seems to be a damp hillside at the  edge of the woods, often beside a street or highway. Coltsfoot was, as its generic name suggests, a popular cough remedy; but it has been known to cause serious liver damage, so it’s not as popular as it used to be.

    Gray describes the genus and the species:

    TUSSILÀGO [Tourn.] L. COLTSFOOT. Head many-flowered; ray-flowers in several rows, narrowly ligulate, pistillate, fertile; disk-flowers with undivided style, sterile. Involucre nearly simple. Receptacle flat. Achenes slender-cylindric or prismatic; pappus copious, soft, and capillary. — Low perennial, with horizontal creeping rootstocks, sending up scaly scapes in early spring, bearing a single head, and producing rounded heart-shaped angled or toothed leaves later in the season, woolly when young. Flowers yellow. (Name from tussis, a cough, for which the plant is a reputed remedy.)

    T. farfara L. — Wet places and along brooks, e. Que. to Pa., O.,and Minn. (Nat. from Eu.)

    Frederic William Stack gives us this description in Wild Flowers Every Child Should Know:

    COLTSFOOT. COUGHWORT.

    Tussilago Farfara. Thistle Family.

    This is the same Coltsfoot that our grandmothers used to gather and dry and hang in the garret along with their Boneset, Catnip, Goldthread, and a various assortment of garden herbs. Coltsfoot was considerably used at one time as a family remedy for coughs and colds, and many a steaming cupful has been sipped by country people for this purpose. Its Latin name, an old one used by Pliny, is derived from tussis, a cough, and ago, alluding to the medicinal use of the leaves. The ancients smoked the leaves of Coltsfoot for relief in cases of asthma. Its fresh juice has been used for affections of the skin, and in Germany the dried leaves are said to be used as a substitute for smoking tobacco. The flowers of the Coltsfoot look something like those of an imperfectly developed, or half-opened Dandelion, but where the flower heads of the Dandelion are slightly tufted or raised toward the centre, those of the Coltsfoot are cupped or hollowed, more like an Aster, with a finely fringed edge. The rather large, solitary flower is borne on a thick, hollow, light green stem, rising direct from the long, slender, creeping perennial root from four to eighteen inches in height. It is usually stained with red and is covered with numerous scalelike and alternating leaflets. The light yellow flower head is of a lighter shade than that of the Dandelion, and is set in a deep, leafy, thimble-shaped green cup. It is composed of many ray and disc florets — an arrangement fully explained in the description of the Asters. The ray florets are fringe-like, and the small disc florets are five-parted. They have an agreeable odour, and as they fade, they turn to red-brown.

  • Groundsel (Senecio vulgaris)

    This ubiquitous weed is found in temperate latitudes throughout the world. The tight little flower heads never open up any wider than what you see here. These plants, growing on a sunny and recently disturbed bank in Beechview, were among the very earliest flowers to bloom in the spring; this picture, in fact, was taken on March 20, the first day of spring.

    Gray’s description of the genus and species follows, but it does not describe the plants in the photograph very well. The on-line Flora of North America remarks that the plants may be “sparsely tomentose when young,” as these plants were. And although Gray gives “July-Sept” as the flowering period, the Flora of North America says “flowering early spring.” In fact these can also be seen very late in the fall, and almost any time in between. The plant blooms very quickly from seed, and seedlings can overwinter; and it seems to present very different habits depending on the time of year.

    SENECIO [Tourn.] L. Groundsel. Ragwort. Squaw-weed. Heads many-flowered; rays pistillate or none; involucre cylindrical to bellshaped, simple or with a few bractlets at the base, the bracts erect-connivent. Receptacle flat, naked. Pappus of numerous very soft and capillary bristles.— Ours herbs, with alternate leaves and solitary or corymbed heads. Flowers chiefly yellow. (Name from senex, an old man, alluding to the hoariness of many species, or to the white hairs of the pappus.)

    Annuals (rarely becoming biennial); stems leafy to the Inflorescence; heads medium-sized, 1 сш. or less high during anthesis.

    S. vulgàris L. (Common Groundsel.) Low annual, 1-6 dm. high. corymbosely branched, glabrate, leafy to the inflorescence; leaves pinnatifid and toothed, 1-8 cm. long, 0.6-3 cm. broad; calyculate bracts (bracteoles) of the involucre distinctly black-tipped; rays none; achenes hirtellous. — Waste grounds, common. July-Sept. (Nat. from Eu.)

  • Zigzag Aster (Aster prenanthoides), white form

    The white form of the Zigzag Aster (for which the preferred botanical name is now Symphyotrichum prenanthoides) is not terribly rare, though far less common than the blue form. Here we see the white form in the foreground, and the blue in the background. All shades between pale blue and white occur, so it’s very hard to mark where blue ends and white begins.

    This plant was growing along a trail in Bethel Park, where it was blooming in early October.

    We repeat the description we gave when we presented the blue form:

    Flowers. Heads about an inch and a quarter wide, in irregular corymbs; disk flowers yellow, fading to red-brown; rays pale blue or violet, sometimes white, linear, numerous.

    Leaves. Variable: alternate; lanceolate or ovate-lanceolate, with sharp and narrow points; strong central rib; rough, outward-facing hairs noticeable when rubbed toward stem; lower leaves on petioles with broad wings clasping the stem; upper sessile and clasping. On some plants the leaves are jaggedly toothed; on others the teeth are less prominent, with the upper leaves almost entire.

    Stem. Tough, wiry; with purplish vertical lines; arching, about 1 or 2 feet high; characteristically zigzag from leaf to leaf, as in the picture at right.

    Gray describes the genus Aster and the species:

    ÁSTER [Tourn.] L. STARWORT. FROST-FLOWER. ASTER. Heads many-flowered, radiate; the ray-flowers in a single series, fertile. Bracts of the involucre mure or less imbricated, usually with herbaceous or leaflike tips. Receptacle flat, alveolate. Achenes more or less flattened; pappus simple, of capillary bristles (double in §§ 4 and 5). — Perennial herbs (annual only in §§ 7 and 8), with corymbed, panicled, or racemose heads, flowering chiefly in autumn. Rays white, purple, blue, or pink; the disk yellow, often changing to purple. Species often without sharply defined limits, freely hybridizing. (Name aster, a star, from the radiate heads of flowers. )

    A. prenanthoìdes Muhl. Stem 1 m. or less high, corymbose-panicled, hairy above in lines; leaves rough above, smooth underneath, ovate to lanceolate, sharply cut-toothed in the middle, conspicuously taper-pointed, and rathrr abruptly narrowed to a long contracted entire portion, which is abruptly dilated into a conspicuously auricled base; heads on short divergent peduncles; involucre 5-8 mm. high; bracts narrowly linear, tips recurved-spreading; rays violet. — Borders of streams and rich woods, w. N. E. to Va. and Ky., w. to Minn, and la. Aug.-Oct.