IDENTIFIED as Common Groundsel (Senecio vulgaris)

This looks like Common Groundsel, but lacks the black-tipped bracts.

Found at Royal Botanical Gardens, Burlington, Ontario. Mid-June. Open area, gravel-ish.

This looks like Cowbane, but the leaves are opposite.

This plant was found July 9/05, along a railroad embankment, above a bog/fen/marsh area. Fletcher Creek headwaters area.

Here's the flower umbel.

• Possibly Valerian (Valeriana officinalis) (see http://www.ibiblio.org/herbmed/pictures/p14/pages/valeriana-officinalis.htm) (CR)
• Valerian (WM)

IDENTIFIED as Tower Mustard (Arabis glabra)

A Mustard, found along Hamilton-Brantford Rail Trail, Jul 4/05; also in Hilton, Jul 8/05.