115 
all specimens studied and tlie fact that the fungus is parasitic on a dif¬ 
ferent, although related, family of plants, make me hesitate to refer it 
to A. amaranthi. 
In 1880 Spegazzini* included in Cystopus cubicus (= Albugo tragopo- 
gonis (Pers), O. Kze.), a form occurring on leaves of Boerhaavia erecta 
found at Barracas del Sur, Argentine. Our species, however, appears 
to differ from A. tragopogonis in at least the following ways: First, in 
having spores yellowish in mass; second, in having the terminal conidia 
smaller than the others; and, third, in the conidia having a dusky-brown 
equatorial band. Besides this the families of the host plants are not 
at all closely related, and from this fact alone it is probable that the 
species are distinct. 
The next reference I find to an Albugo on Hyctaginacese is by Spe¬ 
gazzini,! who, in 1891, described a new species, Cystopus platensis , on 
Boerhaavia from Argentine. As his description may not be accessible 
to all interested, I quote in full: 
15. Cystopus platensis Speg. (n. sp.)-Fung., Arg. pug. I, n. 68 (sub C. calico). 
Hab. In foliis vivis Boerliaviae hirsutae prope Buenos Aires (1880), et prope Cordoba 
(1887). 
Obs. Sori bypopbylli macula primo pallescente dein purpurascente cincti, irregu- 
lares minuti (1-2 mllm. diam.) sparsi v. bine inde laxe gregarii, vix prominuli candidi 
din epidermide velati, dein erumpentes ac pulverulenti; conidia globoso-cuboidea 
(20-22 X 18-20 ju) byalina catenulata, minute densissimeque punctulata (an tantum 
granuloso farcta?), suprema ovata obtusa; cellnlae basales steriles obconico-tur- 
binatae (40-45 X 12-15 ju) crasse tunicatae per aetatem flavescentes. Oosporae ignotae. 
Species praecedenti [C. bliti on Amarantliaceae] peraffinis sed conidiis punctulatis 
majoribus satis, ut videtur, recedens. 
The conidia of the preceding species are given as 16-18 x 15-17 g. 
6. Albugo amaranthi (Schweinitz) O. Kuntze. Rev. gen. PI. i, vol. n. p. 658, footn. 1. 
1834. Caeoma [ § TJredo ( Albugo )] Amaranthi, Scbw. Syn. fung. Am. Bor.,No. 2853. 
<Trans. Am. Phil. Soc., Pliila., new ser., vol. IV, p. 292. 
1874. Cystopus Amaranthi (Scbw.) Berkeley. Notices of N. Am. Fungi, No. 571. 
<Urevillea, vol. in, London, No. 26, December, 1874, p. 58. 
Conidia and oospores in leaves of Ainarantacem. 
On Amarantus chlorostachys , Willd. W. T. Swingle, Ho. 4011, June 
26, 1891, Baldwin, Duval County, Fla. Conidia only, on leaves. 
On Amarantus chlorostachys , var. hybridus. Wats. E. M. Fisher, Ho. 
84, July 25, 1890, Urmeyville, Johnson County, Ind. Conidia and ma¬ 
ture oospores in leaves. E. M. Fisher, Ho. 84, August, 1890, Urmey¬ 
ville, Johnson County, Ind. Conidia and mature oospores in leaves. 
On Amarantus crispus , Braun. S. M. Tracy, May 26,1888, Starkville, 
Oktibbeha County, Miss. Conidia and mature oospores in leaves. 
On Amarantus spinosus , L. W. T. Swingle, Ho. 4012, June 26, 1891, 
Baldwin, Duval County, Fla. Conidia and mature oospores in leaves. 
* Spegazzini, Fungi Argentini. Pugillus primus, No. 67. <Ann. Soc. Cientifica 
Argentina, tomo ix, Abril de 1880, Buenos Aires, p. 177. 
t Spegazzini, Dr. Carolus. Pbycomyceteae Argentime. <Bevistu Argentina de 
Hist. Nat., t. i, Buenos Aires, Feb. 1, 1891, p. 32. 
