172 THE PLANT WOELD 



the growth of the year, and a set of little " sprouting " roots just above 

 that ring of active roots. It must be that this root arrangement com- 

 pels the plant to pull itself down into the ground each succeeding year. 

 The pasque flower, on the other hand, lia\'ing a root system like trees 

 and shrubs, can not thus tuck itself back, but eventuallj^ forms a slight 

 elevation, the soil for which is suj)i)lied by ants and the wind. 



The flower bud, at first surrounded by the silk covered fringes of 

 the involucre, at the time of flowering is raised about an inch above it. 

 But soon after flowering, this little inch long stem rapidly lengthens 

 (eight inches or more), bearing aloft the head of hairy-tailed achenes, 

 while the scape below the involucre does not lengthen at all after flow- 

 ering. This development is moderately shown in the lower light-hand 

 figure. 



Winona, Minnesota. 



It goes without saying that an annual plant must seed everj^ year 

 and go through the whole round of life safely, or it will be destroyed 

 But a perennial, on the other hand, need seed and grow from seedlings 

 perhaps only once in a generation. Mr. Clement Reid, in his unique 

 and valuable work on the " Origin of the British Flora," makes the fol- 

 lowing interesting statements regarding a number of common British 

 plants: 



" The horse-chestnut grows well even as far north as Bergen in 

 Norway, and in Britain it produces abundance of ripe seeds every year; 

 but even in the south of England, as far as I am aware, it never suc- 

 ceeds in establishing itself from self-sown seeds. The common elm 

 ( Ulmus campestris), on the other hand, in England only produces per- 

 fect seed about once in forty years. Forty years is far less than the 

 life time of an elm, and if the tree seeds once in a life time, and the 

 seed germinates, the species may establish itself. Perfect seeds have 

 not come under my observation, and I cannot therefore say whether 

 this elm does grow from seedlings. It is generally said only to occur 

 where planted. The butcher's broom {Euscus aculeatus) is an instance 

 of a plant which just manages to hold its own. After watching it fruit- 

 ing for twelve years in succession, I find that as a rvle only about one 

 plant in fifty produces any fruit, and these are not only few in number, 

 but, as they ripen in November, an early winter may prevent them rip- 

 ening at all. The plant being perennial and hardy can survive, but it 

 has evidently reached its northern limit in Britain. The sycamore, 

 maritime pine and common rhododendron {B. Ponticum) are instances 

 of plants undoubtedly introduced, which seed and grow freely from 

 seedlings in the south of England." 



Have any of our readers made observations on our plants along 

 these lines? 



