Weeds Lab 10/4

Question 1

Answer 1

Common burdock
Asteraceae
B
Sd

Large basal rosette of leaves with hollow lower petioles, and flowers with hooked bracts. Leaves broadly heart-shaped, with hollow petioles and wavy and toothed margins. The undersides of these leaves are loosely hairy and light green. Stem leaves are much smaller, alternate, and egg-shaped.

Question 2

Answer 2

White Heath Aster
Asteraceae
SP
Sd

Basal and upper leaves are without petioles (sessile) and feel rough to the touch (scabrous), slightly toothed margins. Many flowers are produced in panicles at the end of stems.

Question 3

Answer 3

Field pennycress
Brassicaceae
A
Sd

The oval, hairless leaves of the basal rosette and leaves with pointed lobes that clasp the flowering stem

Question 4

Answer 4

Hoary allysum
Brassicaceae
B,P
Sd

tem leaves are alternately arranged,
similar to rosette leaves in shape, but generally point upward and are
smaller with less of a stalk, or stalkless. The margins of all leaves are entire
(smooth to slightly wavy)

Question 5

Answer 5

Shepherd’s purse
Brassicaceae
A
Sd

Question 6

Answer 6

Virginia pepperweed
Brassicaceae
A
Sd

The bottle-brush appearance of mature plants and rosette leaves that are lobed are both characteristics that help in the identification. Leaves that occur along the flowering stem are lanceolate or linear in outline and do not have petioles (sessile).

Question 7

Answer 7

Wild mustard
Brassicaceae
A
Sd

Generally a plant with a winter growth habit that has typical yellow mustard flowers and irregularly lobed leaves with wavy margins toward the base of the plant and much smaller, unlobed leaves at the top of the plant.

Question 8

Answer 8

Common chickweed
Caryophyllaceae
A
Sd

Leaves opposite, broadly ovate to heart-shaped, tips pointed, lower petioled, upper sessile, petioles with single row of hairs. Flowers are small (3-6 mm wide) and consist of 5 white petals that are deeply lobed, giving the appearance of 10 petals

Question 9

Answer 9

Mouseear chickweed
Caryophyllaceae
CP
Sd, Rooting stems

Question 10

Answer 10

White Campion
Caryophyllaceae
A,B,P
Sd

hairy, opposite leaves and lobed, bladder-like flowers

Question 11

Answer 11

Burcucumber
Cucurbitaceae
A
Sd
Vining plant with 5-lobed leaves and small, spiny fruit that resemble cucumbers. Leaves hairy, broadly heart shaped with 5 pointed lobes and a toothed margin.

Question 12

Answer 12

Goosegrass
Poaceae
A
Sd

Flattened stems with a distinctive white or silver center. Plants often appear compressed to the soil, as if they have been repeatedly stepped on. Leaves folded in bud. Additionally, the distinctive white center of goosegrass distinguishes it from most other grass weeds.
The ligule is 1-2 mm long, fringed, uneven, and membranous. Sheaths are flattened, whitish at the base, and sparsely hairy in the collar region.