ON GRAMINE^: 125 



yEcidia on leaves and petioles of Olaux maritima, May; 

 uredo- and teleutospores on Scirpus maritimus, June to August. 

 Banks of the Humber, Hull. (Fig. 76.) 



The researches by which Plowright proved the connection of these two 

 forms are given in Grevillea, xxi. Ill, and in Jonrn. R. Hort. Soc. xii. 

 p. ex. ; other observers have found a similar Uromyces on Scirpus mari- 

 timus and therefrom have produced secidia on other host plants such as 

 Pastinaca sativa (Rostrup), Berula angustifolia, Daucus Carota (Bubak), 

 (Enanthe aquatica (Klebahn), Hippuris vulgaris and Sium latifolium 

 (Dietel), etc. In North America, a morphologically indistinguishable 

 Uromyces on Scirpus Jluviatilis, etc. has produced an secidium on Cicuta 

 maculata (Arthur), and similar aecidia on allied UmbelliferEe are suspected 

 to belong to the same life-cycle. It is evident that U. Scirpi, like Puccinia 

 Isiacae, is in its eecidial stage a plurivorous species, though possibly some 

 of these forms may be separated in the future as " biological " races. In 

 any case, they are not so sharply distinguished as in other instances, but 

 Klebahn isolates our British species as U. maritimae Plowr. See the full 

 account in Sydow, Monogr. ii. pp. 304 — 7. 



Distribution : Europe and North America. 



37. Uromyces Dactylidis Otth. 



JEcidium Ranunculi-acris Pers. Obs. Myc. ii. 22. 



JE. Ranunculacearum DC. Fl. fr. vi. 97 p.p. Cooke, Handb. p. 539 ; 



Micr. Fung. p. 196 p.p. 

 Uromyces Dactylidis Otth, Mittheil. Nat. Gesell. Bern, 1861, p. 85. 



Plowr. Ured. p. 130. Sacc. Syll. vii. 540 p.p. Sydow, Monogr. ii. 



309. Fischer, Ured. Schweiz, p. 71, f. 54. 

 U. graminum Cooke, Handb. p. 520 ; Micr. Fung. p. 214. 



Spermogones. Epiphyllous, honey-coloured, but also a few 

 scattered among the secidia on the lower surface. 



jEcidiospores. iEcidia hypophyllous or on the petioles, 

 seated on yellow spots, in roundish or, on the petioles, elongated 

 clusters, cup-shaped, yellow, with slightly torn, recurved margin ; 

 spores delicately verruculose, pale-yellowish, 17 — 25 /z. 



Uredospores. Sori amphigenous, scattered or in rows, small, 

 elliptic or oblong, long covered by the epidermis, pulverulent, 

 yellow-brown ; spores globose to ovate, delicately echinulate, 

 yellow or yellow-brown, 21 — 32 x 18 — 25 fi ; epispore 1| — 2 /j, 

 thick, with 7 — 9 germ-pores ; paraphyses generally wanting. 



