Flora Pittsburghensis

Author: Father Pitt

  • Late Thoroughwort (Eupatorium serotinum)

    Eupatorium-serotinum-2009-10-24-Oakmont

    Some of the Late Thoroughworts are stlil blooming as October fades into November. They can hybridize with other members of the genus Eupatorium, but this one appears to be a pure strain—note the smooth leaves, with petioles and without teeth, which set this species apart from either Boneset (Eupatorium perfoliatum) or White Snakeroot (Eupatorium rugosum). It was blooming in late October along a seldom-used railroad siding in Oakmont.

    From Gray’s Manual of Botany: Eupatorium serotinum Michx. Stem pulverulent-pubescent, bushy-branched, 1-2 m. high; leaves ovate-lanceolate, tapering to a point, triple-nerved and veiny, coarsely serrate, 0.5-1.5 dm. long; involucre very pubescent. Alluvial ground, Md. to Minn., e. Kan., and south w.

  • Canada Thistle (Cirsium arvense)

    Cirsium-arvense-2009-10-24-Oakmont

    This would certainly be one of our most prized ornamentals if it weren’t prickly, ubiquitous, and ineradicable. The seeds are prized by goldfinches, which are among our most ornamental birds. This plant was blooming in late October along a seldom-used railroad siding in Oakmont.

    Gray describes the genus and the species:

    CIRSIUM [Tourn.] Hill. COMMON or PLUMED THISTLE

    Heads many-flowered; flowers all tubular, perfect and similar, rarely imperfectly dioecious. Bracts of the ovoid or spherical involucre imbricated in many rows, tipped with a point or prickle. Receptacle thickly clothed with soft bristles or hairs. Achenes oblong, flattish, not ribbed; pappus of numerous bristles united into a ring at the base, plumose to the middle, deciduous. Herbs, mostly biennial; the sessile alternate leaves often pinnatifid, prickly. Heads usually large, terminal. Flowers reddish-purple, rarely white or yellowish; in summer. (Name from kirsos, a swelled vein, for which the Thistle was a reputed remedy.) CNICUS of many auth., not L. By some recent Am. auth. included in CARDUUS.

    * * * * Outer bracts of the appressed involucre barely prickly-pointed; heads mostly small and numerous. None of the leaves strongly decurrent.

    13. C. ARVENSE (L.) Scop. (CANADA THISTLE.) Perennial, slender, 3-9 dm. high, the rootstock extensively creeping; leaves oblong or lanceolate, smooth, or slightly woolly beneath, finally green both sides, strongly sinuate-pinnatifid, very prickly-margined, the upper sessile hut smrrcly decurrent; heads imperfectly dioecious; flowers rose-purple or whitish. (Carduus Robson; Cnicus Hoffm.) Cultivated fields, pastures, and roadsides, common; a most troublesome weed, extremely difficult to eradicate. (Nat. from Eu.) Var. VEST!TUM Wimm. & Grab. Leaves permanently white-lanate beneath. Locally established. (Nat. from Eu.) Var. INTEGRIFOLIUM Wimm. & Grab. Leaves  chiefly plane and uncut, or the lowest slightly pinnatifid. Local, Que., N. E., and N. Y. (Nat. from Eu. )

  • Watercress (Nasturtium officinale)

    Nasturtium-officinale-2009-10-22-Wexford-01

    Watercress likes to grow with its feet in the edge of a lazy stream. This colony grew in a little tributary of the Pine Creek in Wexford, where it was blooming profusely in late October. The main blooming season is in the spring, but the cool weather of fall seems to give the plants their second wind.

    Gray lists the plant as Radicula nasturtium-aquaticum:

    RADICULA [Dill.] Hill. WATER CRESS
    Pod a short silique or a silicle, varying from slender to globular, terete or nearly so; valves strongly convex, nerveless. Seeds usually numerous, small, turgid, marginless, in 2 irregular rows in each cell (except in R. sylvestris).  Cotyledons accumbent. Aquatic or marsh plants, with yellow or white flowers, and commonly pinnate or pinnatifid leaves, usually glabrous. (Name meaning a little radish.)  RORIPA Scop.   NASTURTIUM R. Br.

    1. Petals white, twice the length of the calyx, pods linear; leaves pinnate.

    R. NASTURTIUM-AQUATICUM (L.) Britten & Rendle. (TRUE W.) Perennial; stems spreading and rooting; leaflets 3-11, roundish or oblong, nearly entire; pods (1.2-1.6 cm. long) ascending on slender widely spreading pedicels. (Sisymbrium L.; Nasturtium officinale R. Br.; Roripa Nasturtium Rusby.)—Brooks, ditches, etc., originally cultivated. (Nat. from Eu.)

  • Forget-Me-Not (Myosotis scorpioides)

    Myosotis-scorpioides-2009-10-22-Wexford-01

    The “true” Forget-Me-Not is a European import that makes itself at home along brooks and streams; these grew by a little tributary of the Pine Creek near Wexford. Though Forget-Me-Nots are famously blue, we often see pink ones as well. On these particular plants, the newer flowers are pink, fading to blue as they age.

    Gray describes the genus and the species:

    MYOSOTIS [Rupp.] L. SCORPION-GRASS. FORGET-ME-NOT
    Corolla-tube about the length of the 6-toothed or 5-cleft calyx, the throat with 5 small and blunt arching appendages opposite the rounded lobes; the latter convolute in the bud! Stamens included, on very short filaments. Nutlets compressed. Low and mostly soft-hairy herbs, with entire leaves, those of the stem sessile, and with small flowers in naked racemes, which are entirely bractless, or occasionally with small leaves next the base, prolonged and straightened in fruit. (Name composed of myos, mouse, and os, ear, from the short and soft leaves in some species.)

    M. scorpiodes. (TRUE F.) Perennial; stems ascending from an oblique creeping base, 3-7 dm. high, loosely branched, smoothish; leaves  rough-pubescent, oblong-lanceolate or linear-oblong; calyx-lobes much shorter than its tube; limb of corolla 5-8 mm. broad, sky-blue, with a yellow eye. (M. palustris Hill.) In wet ground, Nfd. to w. N. Y., and southw. May-Sept. (Nat. from Eu.)

  • Canada Goldenrod (Solidago canadensis)

    Solidago-canadensis-2009-09-25-Oakmont-02

    Goldenrods are the bees’ best friends. This one, which was blooming in late September, grew in front of a corrugated steel fence near a disused railroad siding in Oakmont. It may be common to the point of superabundance, but there is no more elegant wild flower than Canada Goldenrod.

    From Gray’s Manual of Botany: S. canadensis L. Stem rather slender, 0.3-1.5 m. high, glabrous at least below, often minutely pubescent above; leaves narrowly lanceolate, thin, glabrous above, minutely pubescent on the nerves beneath, mostly sharp-serrate, the middle ones 6-13 cm. long, 5-18 mm. wide; heads tiny, crowded in recurved racemes and forming dense broadly pyramidal panicles; pedicels strongly pilose; involucral bracts linear, mostly attenuate, greenish-straw-color. (Var. glabrata Porter.) Thickets and rich open soil, Nfd. to N. Dak., s. to W. Va. and Ky. July-Sept.