Dichotomous table for gallers on Meum
(incl. Haloscias, Ligusticum)
by Hans Roskam
1a On above-ground parts => 2
1b Nodular swellings on roots. Ligusticum scoticum: Meloidogyne hapla
2a Malformations of vegetative plant parts => 3
2b Inflorescence disfigured, flowers greened. Ligusticum mutellina, scoticum: Tegonotus scoticus
2c Similar malformations on Ligusticum mutellina are induced by: Aceria peucedani
3a Malformations caused by animals => 4
3b Malformations caused by fungi => 4
4a Development of leaf blade stunted, spoon-like deflected downwards, curled; in case of strong infestation yellowing early. Ligusticum mutellina, scoticum: Tegonotus scoticus
4b Leaf midrib and stalks of leaflets shortened, distorted; leaf blades curled and deflected, nest-like. M. athamanticum; Ligusticum mutellina: Philaenus spumarius
5a Galls with sori on their surface => 6
5b Spindle-shaped, vitreous, at first ± pale green, later grey-brown bulges which reach a length of up to 10 mm on stems or petioles but are often only 1 mm across on midrib and veins. Ligusticum mutellina, mutellinoides; Meum athamanticum: Protomyces macrosporus
6a Bulging swellings, yellowish and usually similarly margined on stem parts and main veins of leaves, bearing aecia. Ligusticum mutellina:. Fungus host-alternating; uredinia, telia on Persicaria alpina, bistorta => 8
6b Similar, but brown to black telia bearing bulges => 7
7a Teliospores 3-celled, bearing several long sturdy spines. Ligusticum mutellina; Meum athamanticum: Nyssopsora echinata
7b Teliospores 2-celled. Ligusticum mutellinoides, scoticum: Puccinia thomasii
8a Aecia dense, cup-shaped, the margin not bent outwards. Ligusticum mutellina; Meum athamanticum: Puccinia mei-mamillata
8b Aecia countersunk, opening with pore, not with cup. Ligusticum mutellina; Meum athamanticum: Puccinia bistortae
8c Spindle-shaped, weak swellings on leaf axis and veins, also on stems, soon bearing telia. Ligusticum scoticum: Puccinia halosciadis