Weed (Not Food) for Thought

April 30, 1999
Mayweed chamomile (Anthesmis cotula) is the weed of the month. It is also commonly referred to as dogfennel since it smells like dog urine when crushed, but the true dogfennel (Eupatorium capillifolium) is a perennial, whereas mayweed is a winter or summer annual. It is a member of the aromatic tribe of composites, which also includes pineapple weed (yes, it smells like pineapple) and the sages (Artemesia spp.). The entomologists insect of the month is the Mayfly and the Maybe. So March winds bring April showers, and April showers bring May flowers; Mayflower brought Pilgrims once, but now brings furniture; May is permission, and can is ability: you may plant whenever you want, but you cannot if you cannot get into the field.

Knotweed in the pathway is an indicator that smartweeds (not weed for thought) are thriving in this type of weather (wet and cool). Knotweed (Polygonum aviculare) and smartweed are members of the Polygonum (which means "many knees," because of swollen nodes) genus. The two common smartweeds in Illinois crops are ladysthumb (P. persicaria) and Pennsylvania (P. pensylvanicum). Ladysthumb gets its name from the reddish thumb prints on the leaf. Small hairs are present on the ochrea of ladysthumb but not on the ochrea of Pennsylvania smartweed. There also many other Polygonum members in Illinois, including prickly smartweed, wild buckwheat, and perennial smartweeds such as the escaped ornamental Japanese knotweed (bamboo) and swamp smartweed (P. coccieum), known to farmers as Devil's shoestring because of the strong perennial root.

Lambsquarters, Chenopodium (goose's foot) spp. are germinating and emerging. Once used as spring greens (food), it now acts more like a ram than a lamb, especially in soybeans. It has a bad-smelling brother called Mexicantea found around farm lots. There are 22 sisters (same genus) in Illinois and a bunch of cousins (other genera), including kochia (often resistant to triazine and ALS herbicides) and Atriplex (saltbush or orache), often called narrowleaf lambsquarters.--Marshal McGlamery, Aaron Hager

Author: Aaron Hager Marshall McGlamery