Lab 7: Spring Beauty and Sundews

 

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Plants to key out (and learn):
41. Claytonia virginica (Montiaceae) 'Spring beauty'
Spring beauty is one of the state's spring ephemerals: it leafs out, flowers, sets seed and senesces before the canopy leafs out in the spring. This compressed life cycle is facilitated by rich soils under sugar maple trees. Like many other members of this family, spring beauty has edible leaves but don't eat it in natural areas!

There is a Northern Wisconsin species in this genus with much wider leaves, C. caroliniana.


42. Cerastium fontanum (Caryophyllaceae) 'mouse-ear chickweed'
This spring to early summer-flowering plant is a native of Europe and is a widespread weed of waste places, but moving into forests in temperate North America. This mat-forming plant is hairy and has five deeply notched white petals and five styles. Like most members of the family, the inflorescence is a dichasium (cyme). The genus name comes from the Greek “keras” or “horned” and refers to the horns on the capsule fruit.

43. Chenopodium album (Amaranthaceae - formerly Chenopodiaceae) 'Lamb's quarters'
As you can see the flowers of this plant are not very easy to work with. The floral formula is given, see if you can recognize the parts under the dissecting microscope. This plant also has edible leaves, at least when young. The older leaves are laden with accumulated nitrites. If ingested by cattle at this stage it may cause photosensitivity. Agriculturally speaking, this species is considered a major pest in the U.S.; like many other noxious weeds it was probably introduced on purpose by early settlers for one purpose (food source) or another (ornamental).

Click here to read about cultivated Quinoa, C. quinoa

 

Species to learn:
44. Drosera rotundifolia (Droseraceae) 'Sundew'
This is a carnivorous species. The leaves are covered with glandular hairs that both trap and digest the insect, then absorb the digested nitrogenous goodies. It grows in nutrient-poor sites such as bogs, although Drosera species from other parts of the world can be found in a wide variety of places, such as cliff-sides.

45. Silene latifolia (Caryophyllaceae) 'white campion' or 'bladder campion'
A commonly encountered species in disturbed areas of Wisconsin during the summer and fall, Silene latifolia shows typical characteristics of the Pink family. Can you identify these diagnostic features? Unusual however is the fact that this species is dioecious, having male flowers and female flowers on separate plants.

46. Rumex acetosella (Polygonaceae) 'Sour dock' or 'Red sorrel' or 'Sheep sorrel'
The funny-shaped leaves of this plant have a tart or sour taste hence the specific epithet, which derives from the Latin acetum for vinegar. Generally found in dry open areas, associated with disturbance, and found almost world-wide where ever there are grazing animals.

 

Genera to learn:

47. Opuntia (Cactaceae) 'Prickly-pear'
The common name of this one ought to be obvious. The “pads” of this plant are actually the stem. In this genus the leaves are quickly shed and/or reduced to spines. Where there would be a leaf there is instead a cushion-like area (aereole) bearing spines and sometimes little bristles (glochids). Both the pads and the fruit are edible although this is not, nor probably ever was, a common practice in Wisconsin as it is in more arid areas. We have three species in Wisconsin, one considered endangered.


48. Phytolacca (Phytolaccaceae) 'Pokeweed'
The only Phytolacca species you are likely to come across in Wisconsin is P. americana (10 stamens, 10 carpels). The non-native P. acinosa (8 stamens, 8 carpels) is naturalized at Olin Park. Perhaps most distinctive about this genus is the elongate raceme (a more or less elongate inflorescence with pedicellate flowers arising from an unbranched central axis).


49. Persicaria (Polygonaceae) 'Knotweed,' 'Smartweed'
Wispy to shrubby herbs with swollen nodes, look for the distinctive ocrea. Many contain oxalic acid, detectable by the sour taste of the sap - think of rhubarb from a related genus Rheum. Many also contain calcium oxalate crystals, detectable by intense burning pain - much like swallowing an inside out pincushion.


50. Amaranthus (Amaranthaceae) 'Amaranth'
This family is characterized by minute flowers in variously compound, congested, and confounding inflorescences. Often the stems are reddish due to the concentration of betacyanin pigments. In some parts of South America this plant is cultivated as a 'grain,' in fact, over the years there have been several plans to cultivate it in the U.S. as well. Many members of the Amaranthaceae family have Kranz anatomy (that is, they have C4 photosynthesis).