4o8 



Garden and Forest. 



[Number 450. 



bending- due to the open flowers ; it begins early and may be 

 seen when the plant is in bud. Peduncles arising from the 

 north and the south sides of die stem are found verging to- 

 ward the east from the start, or they curve near the top so as 

 to bring the bud into the position which will be taken by the 

 head when expanded. Those springing from the east side are 

 naturally in place to look eastward, the top of the peduncle 

 curving over. Those on the west side are scarcely disturbed. 

 It would be too great an effort and require too much force to 

 turn them without coming in contact with the stem, and if 

 heliotropism is the force they are in position .to get the rays 

 from the west. Three-fourths of the heads in a symmetrical 

 plant are, therefore, normally in place to turn eastward more 

 or less readily. Even less than the normal fourth are usually 

 found on the west side of the axis of growth. The long con- 

 tinued effort of the plant to bring its leaves into the plane of 

 the meridian seems to have resulted in a preponderance of 

 leaves on the north and south sides of the stem, an approach 

 to a two-ranked arrangement or flattening of the axis of growth, 

 and as the peduncles spring from the axils of leaves and bracts 

 there is the same tendency in the flower-heads. These vary 

 in number from a single head at the top of the stem to twenty- 

 five or thirty on a large, branching plant, from five to ten being 

 the most common number. When they are crowded at the 

 top of a stem or branch, or somewhat bunched in their 

 arrangement, with less freedom for the curvature of the sepa- 

 rate peduncles, the stem bearing the group usually curves to 

 the eastward, the combined weight of the heads probably help- 

 ing in the process. When the heads become old or reach the 

 fruiting stage the peduncles in many cases straighten, and 

 more of the heads when in fruit look upward. 



The heliotropic force is more conspicuous in the flowers of 

 the Prairie Dock, Silphium terebinthinaceum. The heads 

 are smaller and lighter, on more slender peduncles two to 

 five inches long. The stem is usually taller and generally 

 provided with several slender, spreading branches, and is so 

 free from leaves, except at the very base, as to be scape-like. 

 The heads, as a whole, are turned to the east, but between the 

 hours of ten and twelve the majority are plainly seen to face 

 the south-east. The afternoon sun does not draw them any 

 farther around, but they continue in their forenoon position, 

 but look eastward in the morning. In this they manifest a 

 slight tendency to follow the sun. 



The twistingof the leaves and petioles of the two Silphiums 

 and of the Prickly Lettuce to bring them into the meridional 

 and vertical planes is spiral in its character. A stem-leaf with 

 a horizontal base and a vertical tip or upper half is spirally 

 turned. The motion is with the sun, from left to right, or, to 

 use the common illustration, with the hands of a clock. A leaf 

 on the south side of the stem has its upper face turned to the 

 west, one on the north side has it turned to the east, those 

 inserted on the east and west sides are turned around more or 

 less to the south and north, so as to bring their extremities 

 into a position somewhat parallel with the former. This is 

 quite easily discerned in the Prickly Lettuce, a much more 

 leafy plant than the Silphium. The leaves of the Wild Let- 

 tuce, Lactuca Canadensis, frequently show the workings of this 

 same force, the ends of the leaves being more or less spirally 

 rolled from left to right as they are followed around the stem. 

 A quarter of a turn serves to bring most of the leaves of these 

 Compass Plants into the required position. Occasionally the 

 petiole of a radical leaf may be turned through 270 degrees. 

 Evidently the same force is at work here as in twining plants, 

 which for a given species turns them in a definite direction, 

 either with or from the sun. 



My observations on these plants have been made on those 

 growing in the open prairie, where they receive the full sun- 

 light. If they stand by the borders of woods, or in partial 

 shade, owing to interference with the light the results may be 

 quite different, ornot shown at all normally. 



Chicago, ill. E. J. Hill. 



The New Ozark Iris. 

 To the Editor of Garden and Forest : 



Sir, — During the past two years several articles have appeared 

 in Garden and Forest relative to the new Iris found by me 

 in the Ozark Mountains, and named by Mr. J. N. Gerard I. 

 hexagona, var. La Mancei. All these articles have dwelt 

 upon the beauty of the flower and its increase in point of size 

 and intensity of color over the ordinary type of I. hexagona, 

 itself a handsome and striking species. 



I find that in other respects this new Iris departs far from 

 the Hexagona type. It blooms ten days earlier and more pro- 

 fusely. I. hexagona, under our hot suns, ripens its seed- 



capsules by early midsummer, and the foliage dies down 

 immediately after. Farther north this early dying down of the 

 foliage, and consequent ripening of the rhizomes, may not be 

 a characteristic of the plant, as Gray makes no reference to it, 

 but here it is a noticeable feature. The variety, however, 

 keeps green until autumn, the lower leaves alone dying in late 

 summer. 



There is a marked variation in the seed-capsules. In I. 

 hexagona the seed-pod is oblong-cylindric, six-angled, two 

 inches long. In the new plant the capsules are globular, one 

 and one-eighth inches long, and but a sixteenth of an inch less 

 in diameter. The seeds are a trifle smaller also, but of the 

 same general shape and color. 



Pineviiie, Mo. Lora S. La Mance. 



Yarrow as a Lawn Plant. 



To the Editor of Garden and Forest : 



Sir, — In your issue of the 9th instant appears a note in regard 

 to Achillea Millifolium as a lawn plant. The plant your corre- 

 spondent refers to is, without doubt, the European variety, which 

 seems to be quite distinct from the native form. It is not so 

 rigid as our plant, and seems much better adapted for turfing. 

 About ten years ago I noticed it growing on a steep, dry bank 

 near the University buildings in Toronto, and making a very 

 good ground cover where nothing else would grow, and I 

 agree with your correspondent that it is a useful plant in such 

 situations. 



Botanic Garden, Buffalo, N. Y. John F. Cowell. 



Utilizing Choke Cherries. 

 To the Editor of Garden and Forest : 



Sir, — Mr. Waugh's letter, under the foregoing title, in your 

 No. 448, may be confirmed by other experience than his own. 

 It is years since New York summer residents of Vermont ad- 

 ventured to make jelly from choke cherries and found it to 

 be delicious, and even of peculiar excellence. 



The native Vermonters neglect or despise this wild fruit, 

 but that is only fortunate for the people who wish to use it. 



New York. J. E. Learned. 



The Forest. 

 The Burma Teak Forests. — X. 



military men employed as forest officers. 



A LATE article in Garden and Forest noticed the practice, 

 ■**- when forest administration was first organized in India, of 

 employing military officers. The work had to be done, and 

 we could not wait until professionally trained men were avail- 

 able for it. Military officers, and in some cases medical men, 

 were selected ; young men of active habits and good consti- 

 tution, good business capacity, sportsmen or botanists, with 

 tastes which were likely to make them take kindly to solitary 

 life, hard work and exposure in the forests. A number of the 

 men thus selected have done eminent work in helping to build 

 up forest administration in India. Colonel Pearson has the 

 great merit of being the first to protect forests on a large 

 scale and in a methodical manner against the ravages of jungle 

 fires, and he did this, as he himself delights in acknowledging, 

 not only against the powerful opposition of nearly everybody, 

 natives as well as Europeans, but also against the strong mis- 

 givings of his own heart. For to interfere with this ancient 

 institution which cleared the ground in the hot season of incon- 

 venient grass and underwood seemed little short of impious 

 interference with time-hallowed custom. But Colonel Pearson 

 succeeded, and no one was more pleased than he himselt to 

 see the change which took place, as if by magic, in the forests 

 thus protected. This was in 1864, and since that time fire con- 

 servancy is universally recognized as the most important part 

 of forest protection. One-third of the total area of state forests 

 in the British Indian Empire is now every year protected 

 against the fires of the hot season. Another military officer 

 who should here be mentioned is Colonel Bailey, of the Royal 

 Engineers. In 1872 he organized the topographical survey of 

 the forests, and afterward, when the necessity began to be 

 recognized, of providing a large number of professionally 

 trained native forest rangers ; he established the forest school 

 at Dehra Dun, and for many years filled the post of director of 

 that institution, and of Conservator of the School Forests. To 

 these names I might add many others of military officers who 

 in the early days of forest administration in India have done 

 excellent work. On this point I lay great stress in order to show 

 that under certain circumstances, and under good professional 



