5G 



THE NATIONAL GEOGRAPHIC M \ ( V \ / 1 X 1 • 



flower against pilfering invaders. \ long- 

 tongued bee has to thrust its head deep into the 



flower in order to get a sip of nectar, and in 

 this way gets a face-dusting of pollen, which is 

 communicated to the pistils oi other flowers 



visited. 



CRIMSON-EYE ROSEMALLOW 



Hibiscus oculiroseus Britton. [Plate VIII, 

 right I 



One must go to the marshes along the coast 

 of eastern United States to meet the beautiful 

 crimson-eye rosemallow, which flowers from 

 July to September. 



It is a cousin of the gorgeous swamp rose- 

 mallow, described on page s^7 of the June, 

 1916, number of The National Geographic, 

 and is a native American plant, unlike the 

 marsh-mallow, another cousin, which contrib- 

 utes so largely to the confectioner's art. Still 

 another cousin is the okra plant, without which 

 no southern vegetable garden is complete. 

 Some of the mallows bear flowers that are uni- 

 sexual — either male or female, possessing only 

 stamens or pistils, as the case may be. Most 

 of them, however, are bisexual, having both 

 stamens and pistils, but accomplishing cross- 

 fertilization by having the stamens wither be- 

 fore the pistils come to maturity. 



BEACH PEA 



Lathyrus maritimus (L.) Bigel. [Plate IX, 



left] 



The beach pea, rejoicing in numerous other 

 names, among them one denoting a rugged vi- 

 tality — everlasting pea — belongs to the pulse 

 family. Among its cousins are the wild indigo, 

 the rattlebox, the lupines, the clovers, the tick 

 trefoil, the nonesuch, the vetches, the hog pea- 

 nut, the wild bean, and the Texas bluebonnet, 

 which, along with the red clover, was described 

 in the June, 1917, number of The Geographic 

 (pages 497 and 517). 



The beach pea to its admirers mirrors the 

 sea and the heavens — the clear green of the 

 ocean in its leaves and the azure hues of the 

 sky in its petals. It gladdens the sandy beaches 

 of the seashore from New Jersey to the Arctic 

 regions and from southern Oregon to northern 

 Alaska. 



The style of the flower's pistil is hairy on its 

 inner side, and when the nectar-seeking bee 

 lands for a sip of sweetness his movements 

 cause the style to vibrate. It thus becomes an 

 automatic duster, brushing the pollen onto his 

 coat. 



The beach pea, like many other members of 

 the pulse family, has worked out its own sys- 

 tem of cross-fertilization. The clover is a 

 striking illustration of this. Without the aid 

 of long-tongued bees it is unable to set seed. 

 Australia could not grow clover from native 

 seed until it imported bumblebees to fertilize 

 the blossoms. 



COMMON MILKWEED 



Asclepias syriaca L. [Plate IX, right] 



One does not admire the milkweed either for 

 its beauty or its odor, but rather for its cun- 



ning, rts flowers lack brilliancy, and if one 

 breaks the stem it exudes a sticky, milkish juice 

 with a sickening odor. But in its methods of 

 insuring the perpetuation of the species it dis- 

 plays unusual ingenuity in making the insects 

 its servants, and it has been able to girdle the 

 warm and temperate /ones of the earth with 

 its many hundred species. 



Its blossoms are not fragrant to human be- 

 ings, but they possess a wealth of nectar for 

 bees, wasps, flies, beetles, and butterflies. 



When these animated airplanes attempt to 

 effect a landing on a blossom they find the 

 landing stage very slippery : but as they ma- 

 neuver about for a foothold they get their legs 

 caught in line little clefts at the base of the 

 flower. Attempts to extricate themselves serve 

 only to pull the imprisoned leg into a deep slot. 

 Here it encounters a tiny pair of saddlebags 

 filled with pollen. 



With a vigorous jerk the insect is usually 

 able to free the imprisoned leg, but as be does 

 so the pollen saddlebags hang to it. Bees have 

 been caught, according to Blanchan, with a 

 dozen of these tiny saddlebags hanging to a 

 single leg. 



Flying away to another flower, the visitor is 

 caught as before, but in the struggle to free 

 himself be loosens some of the saddlebags ad- 

 hering to his legs in such a way that the pollen 

 they contain will finally find its way into stig- 

 matic chambers. In this way cross-fertilization 

 is assured. 



Only strong-limbed insects can free them- 

 selves from the milkweed blossom ; many a 

 hive bee has been held prisoner until death 

 ended its captivity. 



Any one can study the milkweed's method 

 by holding a house fly by one of its wings on 

 the blossom. Trying to get a foothold, its leg- 

 will enter the slot. Extricate it, and the little 

 saddlebags come along. 



Not only does the milkweed use insects to 

 insure the setting of seed, but it also employs 

 the breezes. Each seed has its own bit of 

 down, light as a feather, and as in ancient days 

 men set out across the seas, in boats driven by 

 the wind, to establish colonies in the ends of 

 the earth, so the milkweed seed sets out on its 

 tufts of down to find a place to grow. 



The common milkweed grows from three to 

 five feet tall, flowers from. June to September, 

 prefers roadsides, fields, and waste places, and 

 is found from the Atlantic coast to the Rocky 

 Mountains and from New Brunswick to South 

 Carolina. It is a cousin of the butterfly-weed 

 described on page 589 of the June, 1916, num- 

 ber of The Geographc. 



SWEETSHRUB 



Calycanthus floridus L. [Plate X, left] 



This delightfully fragrant shrub grows from 

 four to eight feet high. In the north it is prin- 

 cipally a cultivated garden plant, but in Vir- 

 ginia and the Carolinas and westward it grows 

 wild in rich dry soils. It flowers from April 

 to September, usually reaching the height of 

 its season about wheat harvest. 



While best known as sweetshrub, it some- 

 times is called strawberry shrub or Carolina 



