THE CYTOLOGICAL STRUCTURE OF BOTRYORHIZA 
HIPPOCRATEAE 
EDGAR W. OLIVE 
Brooklyn Botanic Garden 
This species of rust, occurring on the host Hippocratea volubilis 
L., was first described by the author, in collaboration with Professor 
H. H. Whetzel, from material collected in Porto Rico in 1916.! It is 
there recorded as a somewhat peculiar form, though somewhat like a 
lepto-Uromyces, with only one spore form in its life-cycle. The fol- 
lowing diagnosis is there published:? ““O. Pycnia wanting (probably 
not formed). III. Telia mostly hypophyllous but sometimes amphi- 
genous or caulicolous, generally from a localized mycelium, sometimes 
from a systemic invasion affecting entire young shoots; localized sori 
densely crowded in more or less orbicular or irregularly shaped, 
somewhat hypertrophied pulvinate areas, I mm.—I cm. or more 
across, the affected areas yellowish when young, when older becoming 
whitish due to the germination of the spores; in older leaves often 
killing affected spots, which turn brown, the resultant rounded, 
swollen dead areas then bearing a striking resemblance to certain 
insect galls. 
“Telia pulverulent, erumpent, from a definite, superficial, ure- 
dinoid hymenium which arises just under the epidermis, without 
. peridium; teliospores uninucleate, borne singly at the end of pedicels 
which arise from a binucleate mycelium 13-14 by 18-24 yu, thin-walled, 
oval, with a rounded apical protuberance, germinating apically at 
maturity to produce each a long, cross-septate basidium (promy- 
celium) bearing 4 basidiospores (sporidia), similar in shape to the 
teliospores and 8 by II—I2 up. 
“Vegetative mycelium composed of coarse intercellular hyphae, 
made up of binucleated cells, some of which send large botryose, or 
irregularly shaped, haustoria into adjacent cells.” 
The generic name, Botryorhiza, is, in fact, derived from the botryose 
character of the haustoria, a striking feature which, so far as I am 
aware, is possessed rarely if at all by other rusts. It is, however, 
1 Endophyllum-like rusts of Porto Rico. Amer. Journ. Botany. 4: 44-52. pls. 
Z—2: » IOL7. 
ZN LGs De Aye 
337 
