Lab 8: Currants and Raspberries

 

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Plants to key out (and learn):
51. Ribes americanum (Grossulariaceae) 'Eastern Black Currant'
Taxonomists formerly placed the Grossulariaceae within the Saxifragaceae, but the latter family has since been defined more restrictively. The name 'gooseberry' is generally applied to members of this genus that have thorns at the nodes (see for example Ribes missouriense); 'currant' is applied to those that do not. Ribes fruits make a delicious jam.


52. Spiraea tomentosa (Rosaceae) 'Hardhack,' 'Steeple bush'
The specific epithet refers to the underside of the leaves which are densely tomentose, that is covered with dense, tangled, wooly hairs. This makes them appear whitish or rufous beneath. Also keep an eye out for the pyramid-shaped terminal inflorescence of pretty pink flowers. Commonly found in open wetlands.


53. Agrimonia gryposepala (Rosaceae) 'Common agrimony'
This Agrimonia differs from others in having glandular-hairy inflorescence stalks and large (up to 1/2 inch long) fruits. It is found throughout the northeastern United States and as a disjunct in the southwestern U.S. Another common name, 'tall hairy groovebur,' refers to the hooked bristles covering the fruits.

 

Species to learn:
54. Hamamelis virginiana (Hamamelidaceae) 'American witch-hazel'
This species is unique in that it blooms in the fall, with flowers persisting through winter. The fruits ripen a year later. Its long, thin yellow petals (maybe reddish) are straplike and might look more like stamens than like petals. It is used to make witchhazel, which has astringent and medicinal properties. If you come across the shrub, be sure to collect it, even without flowers or fruits, as we only have only a few specimens in our collection.


55. Heuchera richardsonii (Saxifragaceae) 'Prairie alumroot'
The leafless stems (scapes) may reach three feet in height. Various sources credit different parts of this plant with being edible. One even claims that "eating the root raw will cure diarrhea."


56. Prunus serotina (Rosaceae) 'Wild black cherry'
This woody, tree-sized member of the Rosaceae is distinctive due to its "burnt potato chip" bark. Most leaves are also densely pubescent along the lower midrib. The wood is highly desired by furniture and cabinet makers due to its beautiful grain. The fruits are coveted by birds but bitter to the human palate.

Genera to learn:
57. Sedum (Crassulaceae) 'Stonecrop'
Stonecrops have small, fleshy, evergreen or semievergreen leaves in a variety of sizes, shapes and colors. As a general rule they have star-shaped flowers. The family name comes from the Latin crassulae for "thickening." They grow in sand dunes, rocky areas, or even as lawn weeds.


58. Rubus (Rosaceae) 'Bramble,' 'Raspberry,' 'Blackberry'
This genus is difficult taxonomically due to hybridization and production of apomictic swarms. Nevertheless, some of the more common species are readily recognizable. The treatment of the genus in Field Manual of Michigan Flora is eminently practical; using it will save you many headaches. The compound or occasionally simple leaves are usually serrate. The tasty aggregate fruits are clusters of drupelets, not berries. Have you ever had the hard, stone-like seeds (achenes) caught in your teeth? The productivity of a given patch depends on the conditions of the year before; a good growing year will yield productive canes the next.


59. Mitella (Saxifragaceae) 'Bishop's cap,' 'miterwort'
This basal-leaved herb is distinctive in woodlands. Like many members of the family Saxifragaceae, the plant sends up a raceme of flowers from the basal leaves. The more common species has two bract leaves on the racme (hence M. diphylla), the other has none and is 'naked' (hence M. nuda). The flowers have an hypanthium that resembles a cap or mitercap worn by bishops.


60. Potentilla (Rosaceae) 'Cinquefoil,' 'Potentilla'
This rather common member of the Rosaceae takes on a wide variety of forms. Many have leaves palmately divided into five leaflets, others have pinnately compound leaves with silvery undersides. There are more than 23 species of Potentilla in the U.S., nine in WI. Cinquefoils that were once placed in Potentilla are now placed in other genera - for example, our shrubby cinquefoil is called Pentaphylloides floribunda in Wisflora but Dasiphora fruticosa in the Field Manual of Michigan Flora, our common silver-weed was switched to Argentina anserina but now back to Potentilla anserina in the Field Manual of Michigan Flora, and our purple-flowered marsh cinquefoil is now Comarum palustre.