227 



BOTANICAL NOTES. 



Bv Dr. Geo. Yasev, Botanist. 



The Flora of Colorado. — Professor Hayden lias recently issued 

 iu pamphlet form a "Synopsis of tbe Flora of Colorado," which embod- 

 ies the results of the botanical investigations of his party iu that Ter- 

 ritory, together with those of several botanists who have made collec- 

 tions iu that region. The work is prepared by Professor Porter, of 

 Lafayette College, Pennsylvania, and Mr. John M. Coulter, who acted 

 as botanist of the survey. Taken iu connectiou with Mr. Watson's 

 Botany of the Fortieth Parallel, it presents in a very satisfactory form 

 our knowledge of the vegetation of that line fiom the Missouri to the 

 Sierra Xevada Mountains. To show the prevalence of certain orders in 

 that region we observe that Astragalus and Carex are each represented 

 by 43 species, Pentslemon by 17, Ranunculus, Potentilla, and Eviogo- 

 num, each by IG, Erigeron, and Aster each by 15, Oenothera, andArte- 

 mesia each by 11 species, and Saxifraga by 13 species. 



Of coniferous trees there are 5 species of pines, aiul 4 of abies or 

 spruce. Of oaks there are but 2 species, both of a shrubby character, 

 - birches, 10 willows, mostly low' shrubs, and of Populus 3 species. 

 These are the principal trees and large shrubs of that region. If a little 

 more time had been taken in the preparation of the work it might have 

 been made more complete, but as it is it will be a valuable aid to 

 those making collections in that region, as well as to all persons inter- 

 ested in its vegetable iiroductions. 



Comptes Bendits for January contains a valuable essay on the pro- 

 duction of gum in fruit-trees, by Ed. Prilling, the substance of which we 

 give below. He treats of the production of gum under three heads, as 

 follows : 



1. Production in vessels. — In the wood of a tree so diseased as to pro- 

 duce gum, a large number of vessels are more or less filled with it either 

 through their entire length or forming a coating more or less thick around 

 them, or on one side. The most recent observers have admitted that 

 the gum results from the disorganization and transformation of the in- 

 side of the walls of the vessels, but an attentive study of the production 

 of gum in the vessels has led me to an different conviction. The gum 

 shows itself first in very tine drops, which increase in size, touch each 

 other, become confluent and form irregular masses, with sinuate edges. 

 This mode of origin of gum contained in vessels appears irreconcilable 

 with the opinion professed by German observers. The examination of 

 large masses of gum taken frooi the vessels of the apricot has led to 

 the same conclusion. These vessels are marked with areolar cavities and 

 a spiral projection formed by a thickening of the cell- walls on the interior, 

 iiud the masses of gum present on their surface furrows corrcsponding 

 to the spiral lines which jut out from the walls of the vessel, and even 

 little projections corresponding to the cavities. It is then very certain 

 that, iu this case, the gum is deposited in the interior of the vessels, and 

 has taken the impres.sion of the interior. This gum is of the same na- 

 ture with that M. Trecul calls ccrdsone. 



2. Production in cells. — Transformation of starch. — Gum is often seen 

 in the medullary ray sand there offers particular interest, because its ap- 

 pearance is connected with the disappearance of the starch originally 

 -contained in the cells. The change of starch into gum has been noted 

 by former observers, but never to my notion precisely described. On 



