Botany Blog Plants of the Northeastern U.S.

July 30, 2010

American Highbush Cranberry

Filed under: North American Native Plants — admin @ 15:39

There are two main taxa of Highbush Cranberry found in the U.S., one native to Europe and the other to North America. The European Highbush Cranberry (Viburnum opulus) has naturalized throughout the northern half of the U.S. and is most easily identified by the presence of distally depressed (cup-shaped) petiole glands. The fruit of this species is unpalatable and mildly toxic.

The American Highbush Cranberry is sometimes treated as a variety of Viburnum opulus (V. opulus var. americanum) or as a distinct species (V. trilobum). Rather than being cup-shaped, the petiole glands of this shrub are club-shaped or columnar. In addition, the leaves often have short sparse hairs above and the lobes tend to be narrower. While the European Highbush Cranberry can be found in a variety of shaded habitats, its American counterpart is mostly restricted to rich woods or the edges of marshes or swamps. It has fruit that is sour but considerably more palatable than the European variety.

American Highbush Cranberry seems to be much less common in many parts of North America than the European. I have come across dozens of specimens in the wild in the last few years and none of them have been native. Then last week I found some native Highbush Cranberry on a research plot in the Tug Hill region of NY. The habitat was a reverting field at the edge of a marsh where the water table was very close to the surface. Here are some pictures.

Overall habit


Leaf shape


 Petiole glands

Petiole Glands

Hairy margin

Hairs on Leaf Margin

July 25, 2010

Cow Wheat (Melampyrum lineare)

Filed under: North American Native Plants — admin @ 17:36

This small plant is an annual hemi-parasite in the Snapdragon family (Scrophulariaceae) . It is associated with acidic, shady habitats on soils that can be peaty, sandy, or rocky. These plants were found along the edge of a pine forest (white pine/red spruce) on sandy soil. The genus name means “black wheat”; apparently when the seeds of this plant were added to other grains and ground into flour the bread made from this mixture turned out black (, 2010).

Cow Wheat

The flowers are bilabiate and white with a yellow throat. Leaves tend to be lance-shaped or linear, with the upper often with a few long teeth near the base.

Cow Wheat

July 18, 2010

Bittersweet Nightshade

Filed under: Naturalized Plants,Uncategorized — admin @ 19:12

Bittersweet Nightshade (Solanum dulcamara) is an herbaceous vine in the potato family (Solanaceae). It is native to Eurasia but has naturalized widely in North America. It occurs in a variety of habitats provided sufficient light is available. Several features aid in identification. First are the purple flowers with five reflexed petals and bright yellow stamens

Bittersweet Nightshade Flowers

The fruit matures from green to yellow, orange, and finally bright red and resembles a small tomato (also in the potato family). The plant gets its name from the reputed taste of the fruit, which is said to be bitter at first but later sweet. While the fruits are said to be less poisonous than the rest of the plant, I have never dared to taste one as all parts of the plant contain solanine which is extremely toxic. While poisonings are rare, fatalities have been known to occur.

Bittersweet Nightshade Fruit

The leaves are somewhat arrow-shaped and often have two or more lobes at the base. The color is dark green and they seldom have evidence of herbivory. The smell of the leaves is perhaps this plant’s most distinguishing characteristic, similar to tomato but much more foul and disagreeable. This trait has come in handy when it has been necessary to identify seedlings in the field.

Bittersweet Nightshade Leaves

July 5, 2010


Filed under: North American Native Plants,Uncategorized — admin @ 22:20

Study plants for any length of time and one will eventually hear the phrase “sedges have edges”. This is because the stems of sedges typically have three angles, distinguishing them from the terete (round in cross-section) stems of grasses. For quite some time that was about the extent of my knowledge of this group of plants. A few years ago I decided to get serious about learning sedges, particularly the species rich genus Carex. One characteristic of plants in this genus is that the achene (seed) is surrounded by a sac known as a perigynium (plural perigynia). Close examination of these structures and the scales subtending them is often key to proper identification of plants in this genus. The perigynia are relatively large and inflated in Shining Bur Sedge (Carex intumescens), shown below.

Shining Bur Sedge

Recently I have been adding photographs and descriptions for Carex species to my Plants of the Northeastern U.S. website. One goal has been to document important details of the inflorescence using a dissecting scope including a ruler marked in millimeters. Recently added pages include those for Carex brunnescens, C. debilis, C. deweyana, C. disperma, C. hystericina, C. interior, and C. radiata.

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