Recognition of Winter Annuals – Part 1

Winter annuals have been appearing in gardens, lawns and landscapes for the past several months. These plants can be recognized through their characteristic shapes, and peculiarities, with a special focus on leaves since many will not bloom until spring.  The human brain has an incredible capacity for visual pattern recognition.  With practice and repetition, most of us can identify the common winter annuals from their earliest stages.  This is very helpful to gardeners and conservation managers, who want to eliminate undesirable weeds before they mature and multiply.

Occasionally, mistaken identities result in humorous plantings in public or private gardens.  In the municipal garden shown below, a small specimen of Senna obtusifolia – Sicklepod – was raised unknowingly as an ornamental shrub.  Watered and carefully tended by the garden staff, it reached huge proportions before someone explained the mistake.  The staff now fights large crops of young sicklepods that come up every spring all over that garden.

Senna obtusifolia
Sicklepod
Shrub

Here is a brief display of a few interesting  visual patterns seen in five winter annuals, and  one summer annual.   All of the plants are very common in the North Carolina Piedmont.  See if you recognize some of them.  The names are listed at the end.

Plant #1

Plant #2 (Perhaps the most difficult of the group)

Plant #3 (Actually blooming in the 2nd photo)

Plant #4

Plant #5

Plant #6 (The summer annual)

The identities of the plants are:

Plant #1 is Galium sherardia  –  Blue Field Madder

Plant #2 is Nuttallanthus canadensis  –  Blue Toadflax

Plant #3 is Scleranthus annuus – Knawel

Plant #4 is Erigeron annuus – Annual Fleabane

Plant #5 is Soliva sessilis – Burweed

Plant #6 is Lobelia inflata – Indian Tobacco

The Blue Toadflax plants seem more like young succulents and are often among the most difficult to identify.  More details about each plant will follow in the next article.

Herb Amyx