Corn speedwell (Veronica arvensis) is a small, weak, low-growing winter annual that thrives in thin open turf and often appears in solid stands. The lower leaves of corn speedwell are rounded and toothed, while the upper leaves are smaller and more pointed. Like the other speedwells, the leaves are both alternate (end of stem) and opposite (base of stem). Corn speedwell is similar in many respects to Persian and ivyleaf speedwell. However, it has the smallest leaves of the three species. Ivyleaf speedwell leaves are thicker and less serrated than those of either corn or Persian speedwell. The entire corn speedwell plant is covered with soft, fine hairs. The flowers are small, bright blue with white throats, and nearly stalkless, whereas those of Persian and ivyleaf speedwell have stalks that are longer than 1 mm. The seedpods are heart-shaped in all three species.

Winter annual broadleaf weeds germinate in the fall or winter and grow during any warm weather, which may occur in the winter, but otherwise remain somewhat dormant during the winter. They resume growth and produce seed in the spring and die as temperatures increase in late spring and early summer. They quickly invade thin turf areas especially where there is good soil moisture. Shade may also encourage growth. A dense, vigorous turf is the best way to reduce the encroachment of this weed. First, select adapted turfgrass cultivars for your area and then properly fertilize, mow, and water to encourage dense growth. Corn speedwell is similar in appearance to Persian and ivyleaf speedwell.

• GROWTH SEASON / LIFE CYCLE
  • winter annual weed
• GROWTH HABIT
  • prostrate, spreading
    Figure 1, Figure 2, Figure 3, Figure 4, Figure 5, Figure 6, Figure 7
• LEAFLET NUMBER
  • one
• LEAF MARGIN
  • rounded teeth
• LEAF HAIRS
  • upper/lower surface
• LEAF / LEAFLET SHAPE
  • lower leaves egg-shaped or round, upper leaves linear
• LEAF WIDTH
  • ¹⁄₂ - 1 inch
• LEAF VENATION
  • palmate
• LEAF ARRANGEMENT
  • lower leaves opposite, upper leaves alternate
• ROOT TYPE
  • fibrous
• FLOWER COLOR
  • blue / purple

Figure 1. Corn speedwell growth habit.

×

Figure 1. Corn speedwell growth habit.

Print Image

Figure 2. Corn speedwell growth habit.

×

Figure 2. Corn speedwell growth habit.

Print Image

Figure 3. Corn speedwell growth habit.

×

Figure 3. Corn speedwell growth habit.

Print Image

Figure 4. Corn speedwell growth habit.

×

Figure 4. Corn speedwell growth habit.

Print Image

Figure 5. Corn speedwell growth habit.

×

Figure 5. Corn speedwell growth habit.

Print Image

Figure 6. Corn speedwell growth habit.

×

Figure 6. Corn speedwell growth habit.

Print Image

Figure 7. Corn speedwell growth habit.

×

Figure 7. Corn speedwell growth habit.

Print Image