3i8 



SCIENCE-GOSSIP. 



ROYLE'S BALSAM. 



By Constance Garlick. 



HTHIS plant, first described by Dr. Royle, in 

 1839, in his " Botany of the Himalayas," 

 was brought to England some time between that 

 date and 1850, and is now what gardeners would 

 call a troublesome weed. It is even making its 

 way in waste ground near houses, and may soon be 

 counted a member of our alien flora. Somewhat 

 surprising is it that a plant from Cashmere, which 

 flourishes at an altitude of 6,000 to 8,000 feet, 

 should be able to make itself perfectly at home 

 in the smirched and shaded English suburban 

 gardens. Indeed, it more than makes itself at 

 home, for it is so successful an aggressor that our 

 present point of view is how to get rid of it. If 

 Royle's balsam were a tender annual how much 

 we should admire it, but just because it is so easy 

 to have it in plenty, and almost anywhere, we 

 are apt to neglect our opportunities of observing 

 an unusually interesting subject. 



This balsam is indeed a plant of many devices, and 

 it works indefatigably throughout its short, active 

 life, from the time the sturdy seedling takes one by 

 surprise as one goes round the garden some fine 

 February day, until, in October, the brave flowers 

 at last dwindle and pale before the night frosts. 

 It has then done its work, having thrown its seeds 

 far and wide for fresh conquests next spring. 



The early start of the seedling in the race is an 

 important factor in the plant's success, as it holds 

 the best chance of space and sunlight against later 

 comers. The stem grows very quickly in height 

 and thickness, commonly reaching six feet and 

 more. Dr. Royle speaks of the plant as "this 

 gigantic species." The whole branch system forms 

 a cone, giving a grand appearance of stability to 

 its really cheap structure. How large a propor- 

 tion of the fabric is water will be seen when one 

 tries to burn the haulms in autumn. Neither time 

 nor material were used beyond the requirements of 

 an annual stem. The roots do not run far down 

 into the soil. Perhaps it has not much depth of 

 earth in its native highlands, but secondary roots 

 are very readily produced from the base of the stem. 

 If from the wind or any other cause, part of the stem 

 lies along the ground, roots burst out from the 

 nodes and form an additional support. From this 

 point, as a new start, the stem grows vertically. 



The leaves have a strong vein parallel to the 

 margin, and it may be owing to this that the blade 

 is so seldom torn. It is even more remarkable how 

 free are the leaves from the ravages of caterpillars, 

 those autumn pests of suburban gardens. The 

 whole plant has a peculiar resinous smell, only 

 slightly disagreeable to us, but judging by its 



repellant effect on larvae it must convey to them 

 acute feelings of dismay and disgust. The hairs 

 which fringe the leaf- stalk to its base are as 

 efficient as a barbed-wire fence against intruders 

 by way of the stem. The leaves are in alternating 

 circles of three. If their position be remarked at 

 noon and again at dusk, it will be seen that they 

 have moved from a horizontal to a vertical position 

 so that the leaves of each circle face one another. 

 Loss of heat by night radiation is thus minimised, 

 and it must be a very valuable saving in the high 

 altitudes of Cashmere, where the difference between 

 day and night temperature is so great. 



The plant begins to blossom in July, and between 

 then and October produces an immense number of 

 flowers ; very few of which fail in their object of 

 setting seed. To attain this, the flowers must have 

 winged visitors, since the pollen is shed before the 

 pistil of the same flower is mature. The plant puts 

 forth attractions which secure the services as 

 pollen-carriers of English bees, both wild and from 

 the hives. The pyramids of purple-pink flowers 

 are visible from afar, while the peculiar smell 

 before mentioned seems to be an indifferent matter 

 to honey-gatherers. For their convenience of 

 entrance the flower hangs from its slender stalk 

 so as to offer a horizontal landing place, two petals 

 of peculiarly irregular shape forming this stage. 

 On this the bee stands firmly. Overhead is 

 the cluster of five anthers joined in a ring. We 

 will suppose these to be in the pollen-shedding 

 stage ; the bee is thrusting her way to the far 

 end of the calyx-pouch where the honey is, a spot 

 marked by converging streaks of colour. The 

 insect forces apart the two petals on which it 

 stands, widening and flattening the flower in such 

 a way as to press the dusty anthers on its back. 

 The exit is amusing to watch. A humble-bee has 

 no choice but to back out, and at last makes a 

 bungling drop into space, while a slimmer and 

 perhaps more intelligent species of bee comes out 

 head first through one or other of the two openings 

 between the calyx and the two lower petals. In 

 either case, the bee emerges well dusted with the 

 pale yellow pollen. If the next flower visited is 

 at the later stage in which pollen-shedding is over 

 and the pistil is mature, the bee will put the pollen on 

 the stigma which now projects where the stamens 

 were before, and cross fertilization is attained. 



The fruit is soon ripe ; it looks tense and glossy, 

 slender at base and top, five-ribbed, and red on the 

 sunny side. When ripe, if touched however lightly, 

 it bursts in a surprising manner. The five ribs are 

 the middle lines of five strips ; these separate from 



