XXII. A NEW SPECIES OF RAZOUMOFSKYA. 



C. O. ROSENDAHL. 



While engaged in the work of collecting the flowering plants 

 and ferns of the west coast of Vancouver island during the 

 summers of 1901 and 1902 excellent opportunity was given to 

 observe the mistletoe which grows in great abundance upon the 

 hemlock of that region. 



The fact is perhaps generally known that this parasite causes 

 peculiar fasciations, the so-called Hexenbesen, of the stem and 

 branches of Tsuga keterophylla and attention is called to this 

 in a recent publication of the U. S. Department of Agriculture.* 



In this paper the parasite is designated as Arceuthobium occi- 

 dentale Engelm. (Razoumofskya occidentals (Engelm.)Kuntze), 

 and it has been generally classed with that plant or with its 

 variety abietinum Engelm. 



Nearly all the specimens of Razoumofskya occidental** 

 (Engelm.) Kuntze, in the Herbarium of the University of Min- 

 nesota, have been collected on various species of Pinus, and 

 Engelmann in the description of the species states that it occurs 

 " on various conifers of the coast ranges and Sierra Nevada," 

 citing Pinus insignis, P. sabiniana and P. ponderosa. The 

 variety is given as occurring on Abies grandis. 



Examination and comparison of specimens show that the 

 plant found on the hemlock differs from Razoumofskya occi- 

 dentalis, ^growing mostly on pines, in being more slender, 

 more loosely branched and in having the staminate and pistillate 

 plants of about equal size. Not infrequently the staminate plant 

 is the larger (Plate XXVII, fig. 5). which is the reverse of the 

 condition met with in R. occidental. The staminate spikes are 

 more slender, less densely flowered, and generally longer than 

 those of the above-mentioned form. 



* Allen, Edward T. The Western Hemlock, Bureau of Forestry, U 

 of Agric., Bull. 33. 1902. 



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