Plants To Know By Sight

Question 1

Spotted Knapweed

Answer 1

Centaurea stoebe
-erect, branched stems
-alternate, linear leaves, only basal leaves are lobed
-stiff bracts on flowers are tipped with black fringes looking “spotted”
–Asteraceae Family

Question 2

Hemp

Answer 2

Cannabis sativa
–Hemp Family

Question 3

Common Tansy

Answer 3

Tanacetum vulgare
-yellow, button-like flowers in flat-topped clusters
-alternate leaves that are fern-like
–Asteraceae

Question 4

Canada Thistle

Answer 4

Cirsium arvense
-flower buds are “tear-drop” shaped and lack spines
-smooth stems lack spines
-spiny, wavy leaf edges
–Asteraceae

Question 5

Field Bindweed

Answer 5

Convolvulus arvensis
–Bindweed Family

Question 6

Garlic Mustard

Answer 6

Alliaria petiolata
-4-petal white blooms
-alternate leaves
-crushed leaves/stems = strong garlic odor
–Mustard/Brassicaceae Family

Question 7

Poison Ivy

Answer 7

Toxicodendron radicans
-shiny “leaves of 3” (trifoliate compound leaf)
-small clusters of white berries in leaf axils
–Cashew Family

Question 8

Purple Loosestrife

Answer 8

Lythrum salicaria
-lance-shaped leaves
-large, showy flower spikes
–Loosestrife family

Question 9

Leafy Spurge

Answer 9

Euphorbia esula
-yellow-green flowers surrounded by paired, heart-shaped bracts
-injured leaves and stems produce a white sap
–Spurge Family

Question 10

Bull Thistle

Answer 10

Cirsium vulgare
-Hairy mf both on top and under leaves (NOT spikey!)
-large flowers are “gumdrop” shaped and spines extend around the base of the flower head
–Asteraceae Family

Question 11

Plumeless Thistle

Answer 11

Carduus acanthoides
-small, 1-2 inch flowers
-flowers surrounded by many spiny bracts
-leaves are wavy, deeply lobed, and edges have yellow spines!
–Asteraceae Family

Question 12

Musk Thistle

Answer 12

Carduus nutans
-“nodding thistle” since flowers are borne on solitary stalks and tend to droop or “nod”
-flowers surrounded by pointed leaf-like bracts
-large flowers, 3 inches

-leaves are dark green with a light green midrib.
-deeply lobed with spiny edges
–Asteraceae Family

Question 13

Palmer amaranth

Answer 13

Amaranthus palmeri
-mistaken for other pigweed sp. but has a sharp spike on the leaf tips
–Pigweed Family

Question 14

Perennial Sowthistle

Answer 14

Sonchus arvensis
-basal rosette
-multiple flowers per stem
-leaves on branched flower stems
–Asteraceae Family