Dichotomous table for gallers on Laser trilobum
by Hans Roskam
1a On leaves => 2
1b Centre of (partial) umbel or stalk of umbel ± swollen, globular to club-shaped. Gall one-to multi-chambered, inner wall covered with mycelium. Each chamber containing a red larva. Lasioptera carophila
2a Bulge-shaped pads bearing yellowish spermogonia and aecia on petioles, -midrib and main veins. Puccinia sileris
2b Leaf tip undulately curved. Trioza sp.