Category: Rosaceae

  • Seven-Sisters Rose

    Rosa multiflora
    Photographed May 20.

    Of all the common names in circulation, “Seven-Sisters Rose” is the most polite. This is a weedy, thorny rambler that covers itself with heavenly white flowers once a year, scenting the landscape with rose perfume. The individual flowers may be a bit sloppy, but the overall effect is dazzling. Then, all too soon, the show is over, and the plant goes back to being a pest. Most of these were blooming next to a parking lot in Peters Township, but the picture directly below was taken in South Side Park.

    Rosa multiflora
    Photographed May 30.
    Rosa multiflora
    The same
    Another one
  • Indian Strawberry (Potentilla indica)

    Potentilla indica

    Indian Strawberry can bloom almost any month of the year, but right now (May 9) the little yellow flowers are everywhere in lawns and sidewalk cracks.

    For a full description, see the Potentilla indica reference page.

    Indian strawberry
    Potentilla indica
  • Indian Strawberry (Potentilla indica)

    Potentilla indica
    Photographed June 16.

    Also called Mock Strawberry. Ubiquitous in lawns, this little weed bears beautiful fruits that look delicious but taste like nothing. Father Pitt has taste-tested these fruits for you, so you will not have to bother. The flavor is not unpleasant, but not pleasant either. If you were starving and came on a lawn full of Indian Strawberries, you would not hesitate to eat more after you had tasted the first; but if you were not starving, you would find no reason to eat more after you had tasted the first.


    In older references this species is Duchesnea indica; modern genetic research shows that it belongs in the genus Potentilla with the Cinquefoils. The common name “Indian” refers not to American Indians but to India, which is in the native range of these plants. Indian Strawberries came here as ornamentals, and they certainly do make an attractive groundcover. In our lawns they are harmless unless you are a grass fundamentalist.

    Indian strawberry

    Gray counts this species as Duchesnea; since the genus Duchesnea is now included in Potentilla, we give his description of that genus as well.

    POTENTÍLLA L. CINQEFOIL. FIVE-FINGER. Calyx flat, deeply 5-cleft, with as many bractlets at the sinuses, thus appearing 10-cleft. Petals 5, usually roundish. Stamens many. Achenes many, collected in a head on the dry mostly pubescent or hairy receptacle; styles lateral or terminal, deciduous. Radicle superior. — Herbs, or rarely shrubs, with compound leaves, and solitary or cymose flowers; their parts rarely in fours. (Name a diminutive from potens, powerful, originally applied to P. Anserina, from its once reputed medicinal powers.)

    DUCHESNEA Sin. INDIAN STRAWBERRY. Calyx 5-parted, the lobes alternating with much larger foliaceous spreading 3-toothed appendages. Petals 5, yellow. Receptacle in fruit spongy but not juicy. Flowers otherwise as in Fragaria. Perennial herb with leafy runners and 3-foliolate leaves similar to those of the true strawberries. (Dedicated to Antoine Nicolas Duchesne, an early monographer of Fragaria.)

    D. indica (Andr.) Focke. Fruit red, insipid. (Fragaria Andr.) Waste ground, grassy places, etc., s. N. Y. and e. Pa. to Fla., Ark., and Mo. (Introd. from Eurasia.)

    Duchesnea indica
  • Japanese Spiraea (Spiraea japonica)

    This attractive bush is a garden favorite, but it seeds itself and can become invasive. It likes a wet location, especially along the banks of a stream. This bush was growing along the Squaw Run in Fox Chapel, where it was finishing up its blooming in the middle of July.

    In the horticultural trade, “Spiraea” is often spelled “Spirea.”

    Gray describes the genus and the species, which in his time had not gained much of a foothold in North America:

    SPIRAEA [Tourn.] L. Calyx 5-cleft, short, persistent. Petals 5, obovate, equal, Imbricated in the bud. Stamens 10-50. Pods (follicles) 5-8, not inflated, few-several-seeded. Seeds linear, with a thin or loose coat and no albumen. — Shrubs, with simple leaves, and white or rose-colored flowers in corymbs or panicles. (The Greek name, from speiran, to twist, from the twisting of the pods in some of the original species.)

    Flowers In compound corymbs.

    Calyx -tube top-shaped, pubescent.

    S. japónica L. f. Stems 1 m. or more high; leaves 7-9 cm. long, glaucous beneath; petals pink to deep rose-color. — Frequent in cultivation, and occasionally escaping, s. Ct. (Graves) and e. Pa. (Introd. from Asia.)

  • White Avens (Geum canadense)

    This unassuming little member of the rose family likes to grow at the edge of the woods; this plant was growing along a trail in Scott Township, where it was blooming in the early July. The white flowers bear more than a passing resemblance to the flowers of blackberries or strawberries.

    Gray describes the genus and the species, which he puts in the Eugeum or Geum-proper division of the genus:


    Calyx bell-shaped or flattish, deeply 5-cleft, usually with 5 small bractlets at the sinuses. Petals 5. Stamens many. Achenes numerous, heaped on a conical or cylindrical dry receptacle, the long persistent styles forming hairy or naked and straight or jointed tails. Seed erect; radicle inferior. Perennial herbs, with pinnate or lyrate leaves. (A plant name used by Pliny.)

    EUGEUM T. & G.  Styles jointed and bent near the middle, the upper part deciduous and mostly hairy, the lower naked and hooked, becoming elongated; head of fruit sessile in the calyx, calyx-lobes reflexed.

    Petals white or pale greenish-yellow, small, spatulate or oblong; stipules small.

    Receptacle of the fruit densely hairy.

    G. canadense Jacq. Stem (0.6-1.1 m. high) and petioles sparingly hairy; leaves soft-pubescent beneath or glabrate, the basal of 3-5 leaflets or undivided, those of the stern mostly 3-divided or -lobed, rather sharply toothed; stipules ovate-oblong, 1-1.5 cm. long, subentire; petals white. (G. album J. F. Gmel.) Borders of woods, etc., widely distributed.