( >ctober 23, 1 909 ' 2 7 



The relative abundance or rarity of the two species seems to be 



the reverse here of what it is in the Atlantic states. 



A noteworthy recent arrival is Tribulus terrestris. This 



was first noticed in 1903, growing along a railway bank at Port 

 Los Angeles (47). During the present summer (1908), a few 

 plants were collected near San Bernardino by Mr. W. G. Wright, 

 and it was found in abundance in the Southern Pacific yards at 

 Colton. The numerous prostrate stems attain a length of eight 

 feet, producing at each short node a single fruit, which when 

 ripe readily breaks up into five one-seeded indehiscent carpels, 

 the edges of which are margined with prickles. With such 

 efficient means for self dissemination it is probably destined to 

 become common and troublesome. It is only within recent 

 years that this European weed has made its appearance in the 

 United States, but it has already been reported from widely sep- 

 arated localities. The most recent authority (48) reports it as 

 occasional in the Atlantic States, and also from Illinois, Ne- 

 braska and Kansas. 



Medicago lupuliiia, a very recent introduction, is rapidly 

 becoming common in damp soils. Melilotus alba has become a 

 frequent weed by roadsides and along fences. Plantago lanceo- 

 lata has now become very common. 



On the other hand, a few weeds which are very aggressive 

 and wide-spread on the other side of the continent, have ob- 

 tained a foothold here, have maintained it for a number of years, 

 but eventually have disappeared. Of these is Daucus Carota y 

 which in 1890 appeared in a suburb of San Bernardino. For a 

 few years it slowly increased its area of occupation, but at lengrfa 

 ceased to reproduce itself. 



Another such is Datura Tat u la. In 1890 I made a note 

 of the occurrence of this plant at San Bernardino (49), where 

 it had there maintained itself, in a limited way, for twenty years 

 and was then scattered over a few acres. For some ten years 



(47) Davidson, Bull. S. Cal. Acad. '£: 43. 



(48) Gray's Man. 7th ed. 536. 1908. 



(49) Zoe 1 : 123. 



