694 



SCIENCE. 



[N. S. Vol. VIII. No. 203. 



/. Axile leaves, subtending the primary 

 axils. 



g. Rameal leaves, on primary branches. 



h. Bractlets, on the ultimate branches. 



According as one or the other of the 

 parts of this leaf-series is more strongly de- 

 veloped, or is suppressed, the plant will 

 change aspect and may be mistaken for a 

 new species. The other two sources of con- 

 fusion now to be considered are the normal 

 and the accidental, or less usual successive 

 terms in the life-history of the species. 

 These are here treated together, distin- 

 guished by number and letter, the normal 

 or usual by the letter N, the accidental or 

 less usual by the letter A. 



N^ Seedling stage, usually with two small 

 radical leaves. 



N^ Radical-tuft stage, often conspicuous, 

 often remaining some years before develop- 

 ing into N'. 



A' Oval-topped stage, frequent in Biotian 

 Asters, the normal cordate radical tuft be- 

 coming topped out with the smaller, thin- 

 ner, oval or other non- cordate leaves. 



A' Plantain-leaf stage, an occasional ex- 

 treme development from the last, the non- 

 cordate leaves becoming the predominant 

 ones, and often resembling Plantago major in 

 size and shape. 



N^ Cauline stage, normally following N'^, 

 the radical tuft sending up an erect leafy 

 stem which bears six of the eight leaf-forms 

 already mentioned. But instead of tak- 

 ing this normal course of development, the 

 plant may enter upon any one of the fol- 

 lowing seven stages which are enumerated 

 as accidental or less usual. 



J.' Intercalary stage, when one or more 

 little leaves are interpolated into the series 

 with much larger leaves above and below. 



A*' Arrested stage, when the gradually 

 diminishing normal series of cauline leaves 

 meets sudden arrest from which it never 

 recovers, a succession of little leaves now 

 continuing into the inflorescence. 



A^ Sprout form, usually with leaves some- 

 what different in form and size from the 

 type. 



A^ Ramified or branch-leaf form, when, 

 after suppression of the main stem, one or 

 more branches rise to replace it, with new 

 direction, and the leaves larger and more 

 numerous, but the leaf-form remaining true 

 to the branch-leaf type for that particular 

 species. 



J.' Bifurcation, either in leaf or stem, 

 arising apparently not from accident, but as 

 a sport. 



A" Opposite leaf state, due to suppression 

 of internodes, especially upon abnormal 

 branches. 



A^ Verticil form, three nodes brought to- 

 gether in inflorescence or rarely in the leafy 

 stem. 



N^ Aestivation, the budding stage; often 

 a very different aspect is taken here from 

 that before or after. 



N^ Flowering stage, beginning with erect 

 terete rays, which are soon tubular by in- 

 volution, and in anthesis may change 

 greatly, according as the following progres- 

 sions become developed or not : 



a. Pedicels lengthen, changing sessile 

 buds into long-pedicelled flower-heads, and 

 dense branches into loose clusters. 



h. Cymose development may prolong the 

 outer branches so as to overtop the central 

 and original inflorescence. 



c. Rays flatten across, becoming flat and 

 rounded. 



d. Rays change position from erect to 

 horizontal, and finally recurved, incurved 

 or pendulous. 



e. Rays change color with age to white, 

 greenish or brownish. 



/. Disks change color early from yellow 

 to red, reddish-brown or brownish. 



g. Disks change from flat to dome-shaped. 



h. Pappus changes color by yellowing, 

 darkening or reddening. 



J.'° Enfeebled state, after close cutting 



