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151. Araceae, the Arum family
Diagnostic family characters
Leaves:. Simple to pinnately or palmately compound, entire. Alternate, basally clustered (basal lvs each with a sheathing petiole), or cauline. Leaves tend to be broad and in some species (e.g. Arisaema, Symplocarpus) the veins form a sort of margin around the edge of the leaf.
Inflorescence: A very characteristic spadix (cylindrical, fleshy axis packed with numerous small, ebracteate flowers) and spathe (large, foliose or petaloid bract +/- surrounding the spadix).
Fruits: Berry.
Habit: Rhizomatous or tuberous perennial herbs, or tiny(!) floating aquatics of former Lemnaceae.WATCH OUT! This family has bundles of needle-like calcium oxalate crystals (raphides) that can cause painful injury to the mouth and throat. Hospitals see many children each summer who have eaten the bright red berries produced by species #151. Take a look at the display case in the entrance to Birge Hall for an exhibit about the largest arum of them all, the Amorphophallus titanum.
Key out species 151: Arisaema triphyllum 'Jack-in-the-pulpit'
This is a forest species, common in oak and maple woods throughout Wisconsin. Easy to confuse with either poison ivy or trillium before it blooms. Related to a really fancy floodplain forest species named green dragon.
152. Liliaceae, the Lily family (sensu stricto)
NOTE ! TNote: Liliaceae is used in the narrow sense here. Older manuals (e.g., Gleason&Cronquist; Wisconsin Flora) and websites (e.g., Wisflora) use Liliaceae in the broad sense to include many unrelated genera. Unfortunately, Field Manual of Michigan Flora (and their website) breaks up the Liliaceae sensu lato into smaller families incorrectly. The Student Herbarium has the correct families and should be checked. Please see the lilioid monocot handouts from lab which illustrate these different families and how different sources place each lilioid genus.Diagnostic family characters
Leaves: Simple, entire, alternate, less often whorled or opposite, cauline or in basal rosettes, parallel veined. Generally sessile.
Flowers: Actinomorphic, hypogynous. Perianth composed of 6 tepals in 2 cycles, usually all petaloid. 3-carpellate superior ovary with axile placentation.
Fruits: Usually a loculicidal capsule, seldom a berry, typically with flat seeds.
Habit: Perennial herbs with bulbs or rhizomes; showy flowers on terminal inflorescences.Recognize this family on site in the field by the annual, strap or ribbon-like leaves, or in some genera more ovate leaves with prominent parallel veins that follow the leaf margin (reminiscent of dicotyledonous arcuate veins). The leaves often have a glossy appearance and are invariably entire. The flowers are also distinctive: three-merous, perianth parts unfused, flowers often pungent.
Key out species 152: Erythronium albidum 'White trout lily'
This small, colonial lily gets its common name from the mottled appearance of the leaves. It is a spring ephemeral, meaning that it flowers, sets seed, and senesces before the leaves are fully unfurled in the canopy above. Like several spring ephemerals, there is a corresponding northern Wisconsin member in this genus: Erythronium americanum, 'yellow trout-lily.' Both of these species are also referred to as dog-tooth violets, the dog-tooth perhaps refering to the shape of the rhizome.
SPECIES TO LEARN:
153. Symplocarpus foetidus (Araceae) 'Skunk cabbage'
This is the first native plant to come into bloom in Wisconsin, in early spring. The spadix generates heat that allows the inflorescence (surrounded by the spathe) to melt any remaining snow, so it emerges before any other plants are out. The heat also volatilizes chemicals that attract insects (like flies) that will pollinate the flowers. This species gets its common name from its leaves, which resemble large cabbage leaves and flourish after the inflorescence has died back. Its distinct smell resembles that of native striped mammal Mephitis mephitis.
154. Clintonia borealis (Liliaceae) 'Yellow bead-lily,' 'Bluebead lily'
This ubiquitous herb of the northwoods forest floor has yellow flowers and bright round blue fruits -- hence the two common names. It is more common in wet forests -- for some reason I always associate it with getting bit by mosquitoes. The fruits are allegedly mildly toxic. The genus is named after a New York politician from the early 1800's. In WI it is found throughout the state but more commonly up north.
155. Trillium grandiflorum ((Melanthiaceae, former "Liliaceae", Trilliaceae in MICH) 'Big white trillium,' 'Large-flowered trillium'
Trilliums are very simple in structure: each plant consists of an underground rhizome that gives rise to individual flowering stems (peduncles) to which are attached three lvs. Technically, these lvs are bracts; peduncles don’t have true leaves. The large, showy, white petals of this species turn pinkish with age. Trillium has traditionally been placed in the Liliaceae, but recently it has been moved to the lilioid family Melanthiaceae.
156. Maianthemum canadense (Asparagaceae, former "Liliaceae", Convallariaceae in MICH) 'Canada mayflower,' 'Wild lily of the valley,' 'False lily of the valley'
Although small (3"-8"), this perennial, rhizomatous herb is one of the dominant understory species of the northwoods. It can have from one to three leaves. It produces small but showy, white, insect pollinated flowers that ripen into little berries. It does not reproduce well by seed but the rhizomes are effective vegetative reproductive organs. A single clone can be up to 20 feet in diameter and can be as old as 60 yrs. A larger Eurasian species, Convallaria majalis, looks like Maianthemum and also goes by the common name 'Lily-of-the-valley' -- but this "true" Lily of the valley is an ecologically invasive weed, a pest in oak savannas and woodland edges. Both genera are now placed in the lilioid family Convallariaceae. Once part of the Liliaceae sensu lato, both genera are now placed in Asparagaceae, although Field Manual of Michigan Flora erroneously places them in Convallariaceae..GENERA TO LEARN:
157. Uvularia (Colchicaceae, former "Liliaceae", Convallariaceae in MICH) 'Bellwort' 'Merrybell'
Two species occur in our rich deciduous woodlands and commonly seen in spring. The plants have sessile or perfoliate leaves on a somewhat ‘drooping’ stem. The somewhat closed, bright yellow to cream-colored flowers with twisted tepals give rise to triangular capsules later in early summer. The genus is now placed in the family Colchicaceae.
158. Lemna (Araceae, former Lemnaceae) 'Duck weed'
Although you many not have realized it you have probably seen this plant many times. It is the diminutive little green plant found floating on almost all of Wisconsin’s waterways. It consists of a flat, oval-shaped thallus, sometimes called a frond, with a single little root dangling in the water. Although Lemna does rarely produce flowers and seeds it primarily reproduces by budding. Some claim that it is the fastest growing higher plant; it can double its mass in as little as 24 hours. It is eaten by both waterfowl and fish.
159. Sagittaria (Alismataceae) 'Arrow head'
Both the common and scientific names of this aquatic plant come from the characteristic shape of the lvs (they are sagittate). The lvs are all basal with petioles typically as long as the water is deep. In some species the lvs are emergent. Often, when lvs are completely underwater they will be ribbon-shaped (as is the case with some of our specimens). The entire family typically produces unisexual white flowers which can be either above, or perhaps rarely, beneath the water’s surface
160.Potamogeton (Potamogetonaceae) 'pondweed'
This is an aquatic plant with dimorphic floating and submerged leaves. Leaves are parallel veined with prominent stipules. Flowers are inconspicuous, wind-pollinated, and produce nutlets which are loved by ducks and other waterfowl. This family and the genus Potamogeton in particular, are difficult to key.