Filtered (205)
Nannyberry flowers occur in 2-5" wide, dome-shaped panicles at the tips of young shoots. Individual flowers are 1/4" across, consisting of a light green calyx with five triangular teeth; a creamy white corolla with five oval lobes; five stamens with white filaments and yellow anthers that protrude well past the edges of the corolla lobes; and a light green or yellow pistil with a short style. The fruit is a 6-10 mm long drupe, initially green but turning dark blue-violet when ripe, containing a single seed. Nannyberry is similar to blackhaw (Viburnum prunifolium, also present in Jackson Park) — both have white flowers and blue-black fruits that are drupes — but nannyberry leaves have a long, narrow tip on their leaves in contrast to the rather blunt tips on blackhaw leaves.

Viburnum

Viburnum lentago

nannyberry [Blooms: Apr-May]

In the spring, American cranberry shrubs produce flattened panicles of flowers 2-5" across that bear two types of flowers — around the edges are five-petaled, white flowers about 1" across that are sterile (lacking both pistils and stamens), while in the center of the cluster are five-petaled, cream-colored flowers 1/4" across that are fertile (with both a pistil and five long stamens). By late summer, the flowers are replaced by bright red "cranberries" (actually drupes with a single seed) 1/4-1/2" across that prove very popular with birds (which distribute the seeds) and our local coyotes (whose scat is full of the seeds). After removing the seed, the tart flesh (high in vitamin C) can be eaten raw or cooked. In the fall, the leaves also turn red. Viburnum opulus var. americanum is said to be distinct from Viburnum trilobum (aka, highbush cranberry) by Illinois Wildflowers (www.illinoiswildflowers.info) and Minnesota Wildflowers (www.minnesotawildflowers.info), but plants.usda.gov insists that the latter is a synonym of the former. Worldfloraonline.org only adds to the confusion by insisting that the two names are BOTH junior synonyms of Viburnum opulus. ITIS.gov says that V. opulus is the correct name for the European species (now introduced to the U.S.) and Viburnum opulus var. americanum is the correct name for the American species. The easiest way to distinguish the two forms (if you care to) is to carefully inspect the nectary glands (extrafloral nectaries) on the petioles. In V. opulus americanum, the extrafloral nectaries are oval, with a concave top and a distinct rim; in Viburnum trilobum, the extrafloral nectaries are round in plan view with a convex top and no rim. Although rare in most of Illinois, guelder-rose (V. opulus americanum) is quite common around the lagoons of Jackson Park.

Viburnum

Viburnum opulus

American cranberry [Blooms: Apr-May]

Cymes of flowers arise from the leaf axils of blackhaw; the cymes are heavily branched but are sessile on the leaf axil. Individual flowers are 1/4" across with a 2 mm long calyx tube with five apical lobes that are shorter than the petals; a tubular corolla with five white, rounded lobes (the "petals"); five stamens with white filaments and yellow anthers extending outside the corolla lobes; and a small (less than 1 mm long), cream-colored pistil. The fruit is a fleshy drupe (like a plum or cherry) about 8 mm long containing a single brown nutlet that is flat on one side; the fruit becomes blue-black as it matures. The fruits are edible and popular with birds. Blackhaw is similar to nannyberry (Viburnum lentago, also found in Jackson Park) — both have white flowers and blue-black fruits that are drupes — but nannyberry leaves have a long, narrow tip on their leaves in contrast to the rather blunt tip and reddish petioles on blackhaw leaves. The stamens in blackhaw flowers are slightly shorter than those in nannyberry flowers but the difference is subtle; leaf form and petiole color are better differentiators.

Viburnum

Viburnum prunifolium

blackhaw [Blooms: May-June]

Many of the upper shoots of downy arrowwood end in 1.5-3" wide, dome-shaped panicles of flowers with slightly fuzzy, light green branches. Individual flowers are 1/4" across with a short, light green calyx with five short, broad teeth; a white tubular corolla with five rounded, spreading lobes; five stamens with white filaments and tan anthers that extend outside the corolla; and a single white style. The flowers have an unpleasant odor described by various sources as "rotting flesh." The fruit is a small (1/4-1/2") drupe (a stone fruit like cherries or a plum) 8 mm long and dark blue-violet to black at maturity. Downy arrowwood can be distinguished from other Viburnum spp. by its (1) its small size (less than six feet tall), (2) the relatively few teeth along the leaf margins (5-10 per side), (3) the short (about 1/4") leaf petioles, (4) the small, narrow stipules at the petiole bases, and (5) its flowers' unpleasant odor. The common name derives from the fact that the straight stems of the various arrowwoods was preferred by indigenous Americans for arrow shafts.

Viburnum

Viburnum rafinesquianum

downy arrowwood [Blooms: Aug–Sep]

Riverbank grape's flowers develop in 5" long, drooping, cylindrical or pyramidal panicles opposite the leaves of new branches (but skipping every third leaf). The flowers are greenish-yellow and are best described as skeletal; they may be either unisexual or (rarely) perfect (both male and female reproductive organs functional). The male and female unisexual flowers usually both occur on the same plant, either in separate or mixed clusters; both male and female flowers are 1/8" across or less, with a minute calyx and five green to yellowish petals that quickly fall off. Male flowers have five very long, pale, erect stamens around a button-like center; female flowers have an ovary with a short style and five short, sterile stamens, often contorted. The fruit are .... grapes — a round berry, 1/4-1/2" across containing 1-4 seeds, initially green but turning blue-black as it matures, often with a white bloom on the skin. You know, grapes. The fruit of riverside grape is often sour until after a frost, then becomes more "sweet/tart" to the tongue. Riverside grape is subject to parasitism by the grape filbert gall midge (Ampelomyia vitiscoryloides), an insect whose larvae produce large, very hairy, conical galls at leaf nodes. This gall midge is restricted to the eastern half of North America; it was first described by Alpheus Spring Packard, Jr. in 1869.

Vitis

Vitis riparia

riverbank grape [Blooms: [May-Jun]

The tips of the upper stems of heartleaf alexanders produce 2-3" wide compound umbels of 7-15 umbellets, each with 10-20 tiny yellow flowers. The central flower of each umbellet is sessile; the rest have short pedicels (a diagnostic character of the genus). Each 1/8" wide flower consists of five yellow petals that remain curled, five stamens with yellow anthers projecting through the spaces between the petals, and two styles. The fruits are a ribbed capsule with a flat top from which the remnants of the styles project. Heartleaf alexanders is restricted to northeastern Illinois, where it is uncommon; it is usually found in drier habitats than its much more common relative, golden alexanders (Zizia aurea).

Zizia

Zizia aptera

heartleaf alexanders [Blooms: Apr/May–?]

The tips of the upper stems of golden alexanders produce flat to slightly rounded compound umbels 2-3" across with about a dozen umbellets of tiny, golden-yellow flowers. Each umbellet has about 20 flowers; the central flower is sessile (or nearly sessile) while all the other blooms in the umbellet are on short stalks (pedicels), a character of the genus. Each 1/8" wide flower consists of an insignificant calyx, five yellow petals that are persistently incurled, five stamens with yellow anthers projecting through the spaces between the petals, and two styles. The fruits are a ribbed (not winged) 2 mm long capsule with a flat top from which the remnants of the two styles project. Golden alexanders prefers full to partial sun and is tolerant of a range of habitat quality. The yellow-flowered variety of meadow parsnip (Thaspium trifoliatum var. aureum) is very similar to golden alexanders but has basal leaves that are simple rather than trifoliate compound, but I have not seen meadow parsnip in Jackson Park. John Hilty (www.illinoiswildflowers.info) warns that "Golden Alexanders should not be confused with Pastinaca sativa (Wild Parsnip), which is a weedy Eurasian biennial. The latter is taller, blooms later, and has more leaflets in each compound leaf." Wild parsnip DOES occur in Jackson Park, but it is relatively rare, twice the size of golden alexanders, has robust, strongly ribbed stems, and a large, flattened, winged fruit. Heartleaf alexanders (Zizia aptera) is also very similar, but only the uppermost leaves are compound; all the lower and middle leaves are simple and heart-shaped.

Zizia

Zizia aurea

golden alexanders [Blooms: Apr/May–?]