1917] LONG—RAVENELIA 61 
visited the type locality of this rust at San Marcos and found an abundance 
of uredinia, especially on the pods. Some uredinia as well as pycnia were also 
found on the leaves. Even at that early date telia were developing and the 
uredinia on the leaves were disappearing. The uredinia which were so abun- 
dant on the pods in May weathered and disappeared so that none were found 
on the pods in November of the same year. 
The writer has seen several thousand trees of Acacia roemeriana infected 
with this Ravenelia in various places in Texas, and only two trees of this entire 
number showed any evidence of witches’ brooms. One tree was found at 
San Antonio and the other at Uvalde, Texas. There were some 1o-15 witches’ 
brooms on each of these two trees. Apparently the germination of the telio- 
spores of this rust occurs when the pods are young and easily infected and yet 
not at the right season to infect the young branches and cause witches’ brooms. 
This rust is closely related to Ravenelia versatilis (Peck) Dietel, a vie noted 
in a previous article’ by the writer. TableIg more — 
salient characters of each of these two species of Ravenelia. From this table 
the main differences between the two species are easily seen 
Ravenelia roemerianae has been collected by the crits a several places 
in Texas and probably occurs wherever the host is present. The rust was 
exceedingly abundant in the vicinity of Uvalde, Texas, in November 1916. 
Every tree of Acacia roemeriana examined by the writer in the mesquite 
Presepis juliflora)-catclaw (Acacia roemeriana) flats was heavily infected; in 
‘leaf on most of the trees was practically covered with the blackish 
telia of this rust. 
RAVENELIA MESILLANA Ellis and Barth. Bull. Torr. Bot. Club_ 
251508. 1898 * : 
(Ravenelia lensiona Sydow, Hedwigia Beibl. ak Toor). 
O. Pycnia, appearing before the uredinia, sparse, amphige- 
nous, in circinating, crowded, orbicular groups | : 
subcuticular, Brussels brown, ——- hemispherical, 40-60 
iat a wR geceests 7 
. Uredinia am 
tawny, oval to elliptical, °. s-1. chon sinty Juve aay ket pe ao 
_ verulent, subcuticular, ruptured cuticle very noticeable; uredinio- 
- Spores oval to subglobose, 15-22 by 20-26 u, ee a - 
SF 19 J 23 oe thick, oo ! 
