Test #2 Flashcards
What soil condition does redroot pigweed thrive in? What adaptations does it have to
allow it to grow well in landscapes?
High N, stimulates seed production, it’s a luxury consumer
What are the two best times to control a perennial broadleaf weed like Canada thistle or
perennial sow‐thistle?
2-4 leaves, early flower bud stage
How are seed of prickly lettuce, common groundsel and dandelion dispersed?
Wind dispersed, anemochory
Name three weeds that can act as an alternate host for aster yellows. How does it enter greenhouses?
Pineapple weed, common groundsel, dandelion.
Aphids, insects with sap sucking parts
What common feature do we see in weeds that are members of the Polygonaceae Family
(ie. common knotweed, wild buckwheat, and curled dock)?
Ocrea
Why are cattails a problem around irrigation ponds?
Reduce water flow
Name 2 weeds from this lecture that grow well in dry, gravelly soils.
Toadflax and common mullein
Name 2 weeds from this lecture that grow well in compacted soils.
Common mullein and Bicknell’s Geranium
Describe the appearance and emergence times of two types of stems common horsetail
produces.
Spring (mid-late April) spore producing cones/strobilus
May - vegetative stems
How does horsetail reproduce?
rhizomes and spores
What adaptation does round‐leaved mallow have for living in dry soils?
Deep taproot
What features of ground ivy and white clover allow them to persist and spread in lawns?
spreading stolons and low growth
Which weed species is an alternate host for Cabbage black ringspot virus and which greenhouse flowering plant can be infected by this virus?
Shepherd’s purse and impatiens
What are three features you can use to distinguish black medic (BM) and white clover (WC)?
BM- central leaflet has a small stalk, yellow flowers, no stolons
WC- all leaflets are attached centrally, white/pink flowers, stolons
What are two ways you can distinguish mouse‐eared chickweed (MC) and common chickweed (CC)?
MC - hair everywhere and sessile leaves, leaves rounded
CC - line of hair, petiolated, lvs pointed
What soil condition are purslane (P) and thyme‐leaved spurge (TS) well‐adapted to and what adaptations does each have for living in this type of soil?
dry gravelly soils
P - C4 plants, stems store moisture
TS - C4 plant and latex to reduce VPD
What are two ways you can distinguish purslane (P) and thyme‐leaved spurge (TS)?
P - alternate leaves, hairless
TS - hairs, opposite leaves
At what time of the year is speedwell noticeable in lawns and gardens and why?
early spring, they are ephemeral, they die back in the summer heat
