12G 



at the same time, are quite handsome, fragrant, and stay in bloom a week 

 or more. It is curious that tinding the phmt in a certain locality one 

 season is no sign that it can be found there next year. 



Tdra.raciiin Taraxacum (L.) Kerst. While watching the effects of tem- 

 perature on the dandelion in Tune .-i number were found which Avere not 

 producing pollen, the heads were perfect in every way. ))Ut had no pollen 

 on the styles or branches of the stij^mas when the bees were excluded. 



The connate anther-tubes, which were of the normal form in all stages 

 of development, were examiiit d under the microscope and not a grain of 

 pollen found in them. The sterde heads were of a uniform pale yellow 

 and lacked the golden tinted center of the fertile heads found growing 

 neai- by. Bees indifferently passed from one kind to the other. Seed was 

 fornu'd on the sterile heads, lint tlnu'e were more a))orted achenes than 

 usual. 



The dandelion is very sensitive to change of temperature, while the 

 absence of sunshine has very little effect. Early in the season the same 

 heads may lie exposed as often as three days in succession, and the in- 

 volucre not lie opened for more than two or three hours at any one time. 

 As the temperatui-(> imreases they stay exposed from early morning until 

 shut up by the falling temperature of the afternoon, and may not open 

 again next day. 



h'licUia str'jx'iis I., produces a large crop of cleistogamous flowers- 

 during late summer and autumn. The flowers are clustered in the axils 

 and hidden by the long segments of the calyx. The change from con- 

 spicuous to concealed flowers involves more than a change from gamo- 

 petalous to apetalous. The stamens are reduced in length to that of the 

 ovary with a small pollen-producing surface at the tip, which is in close 

 proximity to the sessile stigma. The resulting capsuh s are numeious and 

 well filled with seed. 



Falcata coiiiosa (L.) Kuntze sends forth long, slender, stoloniferous 

 runners in early summer that produce apetalous flowers before the con- 

 spicuous blooms appear. Not only is the form of the flower quite differ- 

 ent from that of those coming later, but the early, ovoid, single-seeded, 

 fleshy pod is very unlike the three-seeded, bean-like pod of the later 

 flowers. The mature single-seeded pods are found on or near the ground 

 after the conspicuous flowers have come into bloom. 



If O.ralis stricfa L. produces cleistogamous flowers on recurved scapes, 

 at the base of the plant I have not seen them, but have found flowers in 



