The Seasonal Development, Gross Structure, 



Ecology and Geographical Distribution 



of Sanguinaria Canadensis 



Rhea Olive Baker 

 Botanic Department, University of Pennsylvania 



THE SEASONAL DEVELOPMENT 



Among our earliest spring flowers is the blood root, Sanguinaria 

 canadensis. Quite a while before most early spring flowers have 

 begun to appear, the white buds of the Blood Root show above the 

 leaf litter of the forest floor. 



When, about March first, vSkunk Cabbage flowers first appear, 

 Blood Root sends forth from the growing end of the thick, creeping 

 rhizome its single floral bud. Ma^^-apples, Rue Anemones, and 

 Jack-in-the-pulpits are beginning their season's growth. Blood 

 Root, however, develops much more rapidly. Within the growing 

 tip, which at this time is just about i cm. long is the entire growth 

 for the season. Under favorable conditions the tip pushes upward 

 and appears above ground usually leaf first, in 1918 on March 

 seventeenth. The leaf is tightly rolled and is borne on a delicate 

 stalk which slowly elongates. After two or three days, the growth 

 slows up for a few days. As soon as the leaf and stalk are entirely 

 clear of the ground, we notice that there are two stalks, (that is, 

 if the plant is to produce a flower.) — one bearing the leaf and the 

 other enclosed within the leaf. This second stalk bears the flower 

 bud which, during its development, is carefully sheathed and pro- 

 tected by the leaf. 



From eight to eleven days after the leaf tip first appears above 

 ground, the leaf begins to open very slowly, uncurling slightly every 

 day. As the leaf unrolls, the flower stalk lengthens, and from now 

 on until the flower opens the flower stalk lengthens more rapidly 

 than the leaf stalk. Simultaneous with this lengthening of the 

 flower stalk is the unfolding of the leaf. Eight to thirteen days 

 after the appearance of the plant above ground, the bud shows 

 signs of opening. Over the tightly closed petals are two very pale 

 green, faintly lined sepals. When the bud first appears these 

 sepals entirely close it, but gradually they spread further and fur- 

 ther apart until they drop off. This usually occurs either tlie day 

 before or on the day of blooming, although occasionally the sepals 

 may persist until after the flower has bloomed. 



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