Transformational Gardening

Showy Ticktrefoil (Desmodium canadense): Images

Date Location Notes Images
July 26, 2011 Southeastern, New Hampshire Showy Ticktrefoil is a large plant -- 2 to 6 feet tall with alternate leaves. Each leaf has three large leaflets and sheath at the base of the petiole where it attaches to the stem. The end leaflet has a longer petiole (leaflet stem). The leaflets are entire (untoothed), 2 to 8 inches long, less than half as wide as long, ovate to lanceolate and short-pointed at the tip. However, some of the lower leaves have more oval leaflets as can be seen in one of the pictures below. The stem is very hairy, feels 4-sided and is streaked vertically with red lines.

The flowers are purple, pea flowers that grow on a raceme -- an unbranched inflorescence bearing flowers with short stalks. Older flowers appear towards the bottom of the inflorescence and new flowers are produced as the shoot grows. For Showy Ticktrefoil, the flowers can be bunched closely as seen in the images to the right and below or they can be spread out slightly more than shown in the pictures.

It can be differentiated from other plants in the genus by the hairy stem, large lanceolate leaves (less than half wide as long), and large and often densely-packed racemes of flowers. Panicledleaf Ticktrefoil (Desmodium panciulatum) has similar-looking leaves and leaflets, but the stem is not as hairy (sometimes no hairs), the leaflets are only 1 to 2 inches long, the stem does not have the vertical red lines and the flowers do not appear to be as densely-packed.

At first I thought this was Alfalfa (Medicago sativa), but alfalfa leaflets have teeth towards the tip. In addition, alfalfa only grows to 1 to 2 feet tall.
Date Location Notes Images
June 25, 2012 Southeastern, New Hampshire I had trouble determining whether this was Showy Ticktrefoil (Desmodium canadense) or Hoary Ticktrefoil (Desmodium canescens) because I could not tell if the backs of the leaflets has uncinate (hooked-tip) hairs. See last picture below. However, Hoary Ticktrefoil has a very long petiole, much longer than the terminal leaflet stalk according to the Manual of Vascular Plants of the Northeastern United States and Adjacent Canada. In this case, the petiole and stalk of the terminal leaflet are about the same length and much shorter (combined) than the length of the terminal leaflet. This indicated that it was Showy Ticktrefoil.