A. DRACUNCULUS. 



119 



Panicle dense; 



peduncles 



2 mm. or less long 



Heads 2-3 mm. broad, 

 Inclined to droop; 

 Iv3. I to 3 or 6 mm. \ 

 Inodorous 



Panicle loose; 

 peduncles 

 2-S mm. long 



de. 



This is shown in table 10, where the first 14 collections under subspecies typica are of the 

 American, or " aromatica," type and the last 6 of the Old World type. The latter group 

 includes one collection from California, since it was considered by Rydberg as genuine 

 dracunculus, introduced into America. These counts show that the number of flowers 

 is 21 to 51 for the American form, with an average of 32, and 21 to 42 for the Old World 

 form, with an average of 27. These results would of course be difTerent if a larger series 

 were studied, especially as regards the maximum in both forms, but it is extremely 

 unlikely that the difference between the averages would be sufficient to indicate even 

 a tendency towards a separation. The fig- 

 ures here given are based upon counts in 

 normal, well-formed heads selected from 

 about the same relative position in the inflor- 

 escence in every case. In this connection it 

 may be suggested that the low number some- 

 times obtained for Old World material may 

 be due to the fact that specimens from across 

 the sea are usually less carefully preserved 

 than those from this country, and as a result 

 of this and of frequent handling some of the 

 flowers have fallen out. 



Because of the wide hiatus in geographic 

 distribution, some have thought that char- 

 acters should be found upon which to base 

 a taxonomic separation of the New World 

 plants from the original A. dracunculus, at 

 least varietally. But every attempt thus far 

 made has completely failed. The leaves 

 average perhaps a little narrower, 3 and 4 

 mm. being common widths, but leaves up to 

 7 and 8 mm. wide are not rare. In many 

 cases exact counterparts of European or Asi- 

 atic plants can be found here. The inevi- 

 table conclusion, therefore, is that the most common and widespread form in western North 

 America is not even varietally separable from the Old World A. dracunculus. 



Of the other subspecies, glauca, as now restricted, is a narrow-leaved, small-headed 

 plant with every appearance of being an undernourished or competition form. Yet its 

 occurrence on this continent in greatest abundance toward the east of the range of typica 

 indicates that its characters may be somewhat permanently fixed. It is here made to 

 include A. dracunculoides Pursh. This is in agreement with Gray's treatment (Syn. Fl. 

 P:369, 1884, etc.), except that this author did not use the earlier name and extended 

 the concept to include all of the American plants of subspecies typica. The only differ- 

 ence between glauca and dracunculoides is the loose pubescence on the young parts of the 

 former, and this is variable in amount and in persistence. Geographic distribution offers 

 no aid here, since both forms occur in the northern United States. Even after the most 

 refined segregation, such as that illustrated in the North American Flora, it is necessary 

 to admit the same form, in this case glauca, both in Siberia and in central North America, 

 although no variety of A. dracunculus is known from Alaska or other intervening terri- 

 tory, a distance of over 4,000 km. The subspecies dracunculina is also pubescent when 

 young, but is very different from all of the others in its thin foliage, very open inflores- 

 cence, and delicate, elongated peduncles. These characters do not varj' in unison, as is 

 evidenced by collections with the whole habit, inflorescence, etc., of this subspecies, but 



FiQ. 16. — Phylogenetic chart of the subapecie.s of Arte- 

 miiia dracunculus. 



