BOTANICAL GAZETTE. 247 



ferences is low, yet they may often be turned to g:ood account in the 

 discrimination of related s])ecies. The essential libro-vascular system 

 of the petiole, as displayed on a cross-section, forms either a closed 

 ring or an arc open superiorly between the outer or cortical and the 

 inner or medulhiry tissue; in the first case it is said to be closed or 

 complete, in the second open or incomplete. Very commonly this is 

 the only vascular system of the petiole, ribs, or veins. Not rarely 

 there are additional or accessory Inindles, sometimes external to the 

 essential system, or iniracortical ; sometimes within the arc or ring, 

 or intrameduUary ; occasionally there are both intracortical and intra- 

 medullary bundles. Generally plants of the same order will agree, 

 at least approximately, in having the closed or open system, and in 

 having or wanting the accessory bundles without or within. But, 

 while Acer Pseudo-platanus has a well developed intramedullery 

 cord, A. platanoides has none, and in general the Maples are divided 

 in this resj^ect quite independent of other characters ; and the differ- 

 ence is similar and equally marked between the species of JEscu/us. 

 The oaks, which have been made a special study in this regard, ap- 

 pear to be somewhat equally divided between species provided with 

 and those ^Idestitute of intramedullery bundles; but related species 

 generally belong to the same category, yet not always. For in one 

 case two species, of doubtful distinction until now, are confirmed 

 by the discovery of an anatomical difference of this sort. All the 

 Birches examined want the intracortical bundles and the principal 

 system forms an open arc, and one or two Alders nearly agi"ee with 

 them; while the others have a closed ring and are furnished with 

 intracortical bundles." 



Notes from Colorado. — There seems to be much confusion about 

 the two species of Oxytropls found on the plains. No. 73 of my 

 Colorado collection, named by Dr. Gray 0- Lamberti^ is of interest 

 because it is the "-Loco" so dreaded by stock men for its poisonous 

 properties. No. 14 is Q. campesiris and a full description of the two 

 would show that they differ materially from the two species of Gray's 

 Manual and the Synopsis in King's Report. 



Malvastrum coccineii^ia is poisonous. Mr. Ruble, a stock man of 

 Pueblo, lost twelve hundred sheep in four hours from eating this 

 plant, in October of this year. Specimens of the plant were sent me, 

 which prove to be the above without any doubt. The Agricultural 

 Department at Washington has received similar reports from other 

 sources, on the poisonous proi3erties of this plant. 



