Weedy Habitat Page 4


Fig.35 Dandelions at edge of sidewalk	Fig.36 Dandelions and sidewalk	Fig.37 Shepherdspurse and dandelions	Fig.38 Knotweed at intersection of sidewalks

This wouldn't be a very good weedy habitat website if I didn't include some photos of the good-ole sidewalk environment. Everyone has noticed that dandelions just love to grow along the edges and cracks of sidewalks. Since dandelions have a long tap root, all they need is a small amount of soil surface to survive. The unused spaces next to sidewalks in Fig. 35 or the cracks between sidewalk slabs in Fig. 36 offer great opportunities for dandelions. The dandelion in Fig. 37 is joined by another weed with a tap root, the shepherdspurse.

Figure 38 shows a great example of how the tendency for people to cut corners has created a niche for some knotweed. The grass in the intersection of these two sidewalks has been worn away by human foot traffic. The prostrate knotweed is able to withstand the traffic.


Fig.39 Prairie threeawn near tracks	Fig.40 Ground ivy near tracks	Fig.41 Weedy railroad bridge

The areas around railroad tracks are always susceptible to "weedy attacks". Railroad companies want to keep their railways clear of any obstructions including any and all weeds. Prairie threeawn, which is a shorter grass, is growing near the tracks in Fig. 39, as is some ground ivy in Fig. 40. The border around the railroad bridge (Fig. 41), may be harder to weed. It has some perennials, grasses, and even a liana (on the pole) growing in it.


Fig.42 Stop light control box	Fig.43 Perennial by a pole	Fig.44 Weeds under a mailbox	Fig.45 Weedy water utility area

Public structures such as stop light control boxes, telephone poles, mail boxes, and water utility areas aren't regularly monitored for weeds.


Fig.46 Weeds in a coal pile	Fig.47 Tubular dandelions	Fig.48

I even found weeds growing in a coal pile. There were no weeds in the middle of the pile, but near the edges where rock and some soil had managed to mix with the coal, weeds could be found. In Fig. 46, it looks like there is a low area in the middle of the photo that has a higher density of weeds. Perhaps this is a run-off area for rainwater.

The dandelions in Figures 46 and 47 appear to be taking advantage of the tubing laying near the coal pile. In Fig. 48 the slightly curved line of dandelions suggests that a tube had once been lying there. The dandelion seeds were probably trapped under the tube and may have been protected from discovery or provided a better habitat then if they had landed away from the tube.

You will have to look closely in Fig. 49 to see several dandelions growing in the cracks around the border of this inner courtyard. Once again, the wind dispersal mechanism has paid off for the dandelion. It has successfully invaded an area that is relatively isolated, except from the sky.