i66 THE PLANT WORLD. 



sun, it was noted that under the lath the purslane failed to grow, ex- 

 cept at a very feeble pace, while alongside in the full blaze of the 

 sun, it was rampant. 



The purslane flower is inconspicuous, but of a bright yellow as it 

 holds itself to the morning sun and closes long before the day is 

 finished. Looked at closely, these blossoms are found to have their 

 stamens sensitive, and when some tiny insect comes for the pollen, 

 the filaments will bend toward the center and bring the anthers close 

 to the pistil. 



The purslane dies with the coming of the autumn frosts and be- 

 neath the blackened network of herbage there falls a crop of seed 

 that in the ratio of multiplication would startle a Matthus. A single 

 seed produces a plant that, if not crowded by its neighbors or over- 

 turned in its growth by the hoe, will thrive and ripen a million off- 

 spring as an inheritance of evil to the negligent gardener. 



It is surprising how rapidly form these minute black seeds, shaped 

 somewhat like some sea shells and rougher than most of them. Only 

 a single week is needed from the time of pollination to the maturing 

 of the green oval pod with its contents of a hundred shining seeds. 



To the collector the purslane is a wonder, as it defies the desic- 

 cating effects of weights and dryness, and even grows after it has 

 been placed in press, and is a veritable "live -forever" without the 

 name. 



The Portulaca is remarkable for the lack of a long list of fungi ; 

 in fact there is but one usually met with and that is the white mould 

 Cysyopus Porttdacc^ (DC), which is frequently a destructive enemy. 



In connection with this parasite there is one fact of special in- 

 terest, namely, the tendency of the Cystopustized stems to grow up- 

 right. A plant may have all of its five or six main branches flat upon 

 the ground except one, which with its smaller stem and dwarfed, 

 crumpled leaves, may rise bolt upright from the prostrate branch to 

 the height of several inches. It would seem as if there was a design 

 in this, for these stems are more apt to be hit by any passing object 

 and the spores thereby distributed. A microscopic examination of 

 the stems shows that the diseased stems have a larger percentage of 

 starch than in the healthy ones. In the latter it is quite closely con- 

 fined to the sheath of cells just outside of the wood, but in the in- 

 fested stems it is widespread through the soft cellular tissue. 



Rutgers College, January, 1899. 



It is estimated that oat smut alone destroys each year in the 

 United States over $18,000,000 worth of grain. — Woods, in Year Book 

 of Dept. Agr. for i8g8. 



