ON UMBELLIFER.E 187 



to have been shown experimentally that the Eecidia and the teleutospores 

 described above are genetically connected. The markings on the teleuto- 

 apore are really little, round, densely crowded pits, not actual reticulations 

 as in P. Chaerophylli. - Plowright's statement {I.e. p. 270) that this 

 secidium was found by him on Conopodium denudatum is a mere slip of the 

 memory, as I am informed by Mr W. G. Smith, in whose company it was 

 found at Leagrave, near Dunstable, on the date mentioned. 



Distribution : Western and Central Europe, Algeria. 



59. Puccinia tumida Grev. 



Puccinia tumida Grev. Flor. Edin. p. 430 (1824). Sydow, Monogr. 



i. 376. 

 P. Bunii Winter ; Plowr. Ured. p. 206. 

 P. Umbelliferarum DC. ; Gooke, Micr. Fung. p. 208 p.p., pi. 4, f. 71 — 2. 



Uredospores. Very few, oval, pale yellow, sparsely verrucu- 

 lose, 20 — 25 x 15 — 18, mingled with the teleutospores. 



Teleutospores. Sori on the leaves, more often on the petioles 

 and nerves, minute, but many crowded 

 together and confluent in thickened 

 elongated masses (up to 1 cm. long), 

 covered by the ash-coloured epider- 

 mis, for a considerable time, black- 

 brown ; spores ellipsoid to ovate, 

 rounded at both ends, not thickened Fig. 135. P. tumida. Teleu- 

 above, hardly constricted, smooth, <q^ mesospore and ure- 



brownish, 26 — 36x14 — 26/a; pedicels 



hyaline, short, deciduous ; an occasional mesospore is found. 



On Carum rnajus (= Conopodium denudatum = Bunium flexu- 

 osum). Not uncommon. April, May. (Fig. 135.) 



Formerly confounded with P. Bulbocastani, from which it is distin- 

 guished by its very different habit. In that species the teleuto-sori 

 are usually isolated on the leaves, and cause no swelling of the affected 

 part as P. tumida always does : the latter moreover is without ajcidia. 



Plowright states that the mycelium is perennial, but this is doubtful. 

 The sori appear to be confined to the radical leaves ; I have never seen them 

 on the cauline leaves or (what practically means the same thing) attacked 

 plants do not flower. The fungus should therefore be looked for early, 

 before the radical leaves begin to fade ; the affected plants are then easily- 

 distinguished by their yellowish appearance. 



