8 SYSTEMATIC BOTANY. 



cabbage, radish. But you can do nothing with double flowers. A sweet pea could be 

 made to tell its proper or generic name in this way: 



The sepals and petals together more than six, and petals not all united, brings 

 us again to Division 1. This time "A. STAMENS MORE THAN TEN" 

 is wrong. We take "B. STAMENS TEN OB LESS." "Ovary or ovaries 

 superior," etc., is right, but * "pistils, more than one, not united" is wrong. We 

 therefore look under "* * Pistil only one, simple or compound." The line marked 

 "a" is wrong; so, also, is "6," but "c. Herbs: leaves alternate" describes our 

 plant. "Corolla regular (petals alike) or nearly so" is wrong, so we take the next 

 long line " corolla irregular," etc. Reading under that the five lines beginning with 

 the word "stamens, we have no doubt that the first one, leading to the order 

 Leguminosse, is the right one. Turning to that order and onward, as before, w e 

 find a key in which the following leading lines are correct: " 2. Stamens all united 

 or one above distinct: herbs (except some in 3 and 7). * * * * Leaves pinnate, 

 finding in a bristle, imperfect leaflet or a tendril Style flattened, usually twisted half 

 around, one side hairy, 13." Seven pages further on we find: "13. Lathyrus, 

 Linnaeus." Since this plant is not a native of our country, we do not look further than 

 to note that there are about a dozen kinds which are natives. 



When you think you have correctly determined the name of a plant, turn back 

 to the description of the order, and read it carefully once more, so as to be doubly 

 sure. Then if there is any new matter under the order heading read that also. If, for 

 example, you have traced a very common plant to the genus Phacelia, Euphacelia, 

 and have concluded that it is the tenth species described on p. 150, turn back to the 

 order Hydrophyllaceae, on page 54. Under the same genus and section there, near 

 the bottom of page 55, you find statements which may change your first decision. 

 What you have taken for Phacelia tanacetifolia may be Phacelia distans or Phacelia 

 leptostachya. 



Your labels should be written on slips of paper three inches long, and half as 

 wide. Let the name occupy the upper half, and on the lower half write in small letters 

 where the specimen grew and when you collected it. The label should be fastened in 

 the lower right-hand corner of the sheet on which you mount the plant. Only the left 

 hand end should be pasted down. Paper 17 x 22, cut crosswise, and folded to the size 

 S| x 11, is a suitable size fora school herbarium. The plant should be mounted on the 

 third page of the folded half-sheet. 



