284 



^NATIVE PLANTS IN FIELD, FOREST AND GARDEN. 



table kingdom further than the Droseracecc for the truly 

 marvelous. This family of small and inconspicuous 

 plants does not boast of many members, and although 



Fig. 4. Bird's Foot Violet. 



by no means rare, even those best known in botanic cir- 

 cles are comparatively unknown to the general public. 

 Darwin's interesting book on insectivorous' plants has 

 brought Drosera yotundifolia — the round-leaved sun-dew 

 — into greater prominence than any other member of 

 the sun-dew family. No other variety grows so freely 

 or has so wide a geographical range — extending from the 

 Arctic region to the Cape of Good Hope, Madagascar 

 and Australia in the Old World, and in the New World 

 from Canada to Terra del Fuego. 



The banks of small lakes and mountain streams are 

 often lined with it. The plant is small and so embedded 

 in moss that it easily escapes the eye of the casual 

 observer. It bears from two to six leaves, orbicular in 

 form ; the concave surface of the leaves is covered 

 with tiny red hairs or gland-bearing tentacles, as they 

 are more properly called. Each gland is surrounded by 

 a viscid secretion, which, glistening in the sun, has given 

 rise to the poetic name of sun-dew. The average num- 

 ber of glands on^^fair-sized leaves, as estimated by Dar- 

 win, is 192. Possibly English species grow larger than 

 ours. Thisglandulous element constitutes the wonderful 

 part of the plant. These glands are not only sensitive 

 to the slightest pressure and capable of motion, but 

 exude a secretion having marked digestive qualities, 

 analogous to the gastric juice in the human system. 



Obviously Drosera rotiindifolia is a carnivorous plant, 

 feeding mostly upon small insects which alight upon its 

 leaves by chance, or are attracted thither by its odor. 

 It is difficult to find a well developed leaf which does 

 not bear evidence of the slain ; legs, wings and other 

 hard parts of insects are not acceptable food. 



Darwin's laborious experiments have proved conclu- 

 sively that only nitrogenous substances are digested by 

 the drosera. ' ' That a plant and an animal should pour 

 forth nearly the same secretion adapted for digestion is 

 a new and wonderful fact in physiology." 



Unsuccessful attempts have, however, been made to 

 produce artificial digestion by an extract of the plant ; 

 yet the plant is capable of digesting and assimilating 

 small particles of meat and other substances placed 

 upon its leaves. Leaves thus stimulated make a more 

 rapid growth than others left to get their living in the 

 natural way. Small white flowers appear in August ; 

 they are borne on a sort of one-sided raceme, which 

 nods at the undeveloped apex, so that the fresh-blown 

 flower is always highest. My plants under glass at- 

 tempted to force the season by throwing up long flower- 

 stalks the first of July; the buds seemed full and well- 

 developed, but for lack of reserve strength or other 

 cause never opened. The plants I left exposed to the 

 air were less ambitious and proved to be extremely sen- 

 sitive, especially to a bit of neglect, and perished for 

 lack of a timely drink. The roots of the plant are 

 poorly developed and serve only to absorb water for the 

 plant — a very necessary element in the economy of 

 the drosera, as experience teaches, and its natural en- 

 vironments indicate. 



Few even among scientists would care to follow the 

 careful and exhaustive analysis of the plant made by 

 Prof. Darwin. Nevertheless, a superficial study of the 

 drosera is fascinating and instructive. The blade of 

 the leaf, as well as the tentacles, are capable of motion ; 

 hence the edges are often curled inward, thus forming a 

 sort of temporary stomach. The glands close over 

 their prey, draw it down toward the center, pour their 

 acid secretion over it, and the work of death and diges- 

 tion goes on before our eyes. One authority gives the 

 unfortunate insect fifteen minutes more of life before 

 the secretion closes its tracheae. The time required for 

 the inflection of the glands and the work which follows 

 varies greatly with the quantity and quality of the sub- 

 stances placed upon the leaf. Experiments with all 

 manner of animal matter have been tried to test the 

 digestive powers of the secretion. 



" Fibro-cartilage " (from between the vertebrae of the 

 tail of a sheep) and " bits of the skinned ear of a cat " 

 were served up on the leaves of drosera for the benefit 

 of science by the illustrious Darwin. Common mortals, 

 however, who do not care to invade the sheep-fold or 

 puncture the ears of the family cat, will doubtless be 

 content with more simple experiments ; bits of meat, 

 cooked or uncooked, are within the reach of all. 



Having a quantity of the sun-dew, gathered in early 

 summer in a Vermont pasture, I placed part of it in a 



