Flora Pittsburghensis

Rosaceae

Rose Family

Physocarpus opulifolius

Spiraea alba

Spiraea tomentosa

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. It blooms in late June and into July, with clusters of little rosy pink flowers with long, pink-headed stamens. (In the horticultural trade, “Spiraea” is often spelled “Spirea.”)

Aruncus dioicus

Gillena trifoliata

Pyrus malus

Crabapple (Malus coronaria).Crabapple trees especially like the edge of the woods, or an open woods with clearings. They bloom in late April and continue into early May. The flowers vary from white through pink, the buds being much darker than the flowers.

Amelanchier intermedia

Amelanchier arborea

Crataegus…

Fragraria virginiana

Waldsteinia fragrarioides

Silvery Cinquefoil (Potentilla argentea). Originally from Europe, this little flower joins the herds of little five-petaled flowers in our fields. The minimalistic leaflets are dark green, shiny, and somewhat leathery. It begins to bloom in June.

Potentilla recta

Norway Cinquefoil (Potentilla norvegica). Also called Rough Cinquefoil, because it has rough hairs all over. This paradoxical cinquefoil has three leaflets rather than five. It grows in waste places and isn’t too particular about soil; this plant grew in the middle of a gravel driveway near Cranberry, where it was blooming in mid-June.

Common Cinquefoil (Potentilla simplex). This plant looks very much like Indian Strawberry until we notice that the leaves apparently have five leaflets rather than three; we say apparently, because Gray tells us that the leaves are “3-foliolate but apparently 5-foliolate by the parting of the lateral leaflets.” The plants spread by wiry little runners; see the picture at the bottom of this article. These plants were blooming in early May in the lawn of the Allegheny Cemetery.

Potentilla indicaIndian Strawberry (Potentilla indica). This little creeper, found in shady lawns everywhere, bears bland, tasteless fruit that looks like wild strawberries, but it’s easily distinguished by its yellow flowers. Children like to tell each other that the fruit is poisonous and then dare each other to eat it. It’s perfectly edible, but not really worth eating. It is nevertheless much valued by herbalists, who suppose it to have useful medicinal properties. The blooming season is extraordinarily long, and Indian Strawberry can bloom in midwinter if encouraged by a warm spell.

White Avens (Geum canadense). This unassuming little member of the rose family likes to grow at the edge of the woods. It blooms in the middle of the summer. The white flowers bear more than a passing resemblance to the flowers of blackberries or strawberries.

Geum virginianum

Geum vernum

Purple-Flowering Raspberry (Rubus odoratus). The beautiful flowers of this plant vie with wild roses (Rosa spp.) for spectacle, and indeed it is often planted as an ornamental. In the wild, it prefers a semi-shaded hillside, blooming in late May. The leaves are more or less maple-shaped. The raspberry-like fruit, alas, is no good for eating.

Blackberry (Rubus allegheniensis). Blackberry canes are full of thorns, but they give us blackberries, so who are we to complain? The flowers that precede the berries are like little white roses, as befits a member of the rose family—but curiously wrinkled and untidy roses, as if they had slept in their petals after a long night of exhausting revelry.

Rubus…

Agrimonia gryposepala

Agrimonia rostellata

Soft Agrimony (Agrimonia pubescens). These delicate racemes of yellow flowers appear in the open woods, and you are likely to miss them if you are not looking for them. They bloom in early August. Older references usually list this as Agrimonia mollis, a synonym.

Rosa palustris

Rosa carolina

Rosa multiflora

Memorial Rose (Rosa wichuriana). Also known as Rosa luciae. This is the familiar pink rambling rose of roadsides and banks in the city and suburbs. It often persists around old homesites, but it also seems to appear spontaneously often enough that we can regard it as a naturalized citizen of our flora. The large single flowers with shallowly notched overlapping petals and very regular elliptical toothed leaflets are distinctive.

Prunus americana

Prunus persica

Prunus avium

Prunus cerasus

Wild Black Cherry (Prunus serotina). These fine large trees produce an abundance of little white flowers in narrow racemes, followed by tasty black fruit. The crinkly rough bark of mature trees is distinctive. The similar Choke Cherry (Prunus virginiana) also carries its flowers in narrow racemes, but its fruit is red, its bark is smooth, and it rarely grows into more than a medium-sized tree.

Prunus virginiana


Index of Families.