January, 1903.] 



KNOWLEDGE, 



19 



petals, from the base of the caljx-tube ; their filaments 

 are usually united in the lower portion into a tube, which 

 surrounds the ovary ; their free ends curve upwards, fitting 

 the upward curve of the keel, along the bottom of which 

 they lie. The ovary is one-celled, capped by the long 

 style, which follows the curve of the stamens. The blossoms 

 generally j)ossess a brilliant colour — yellow and red being 

 the prevailing tints among our British species — and an 

 attractive odour. These flowers are essentially constructed 

 to be fertilized by bees. The brilliant upeurved standard 

 renders the flower conspicuous. The horizontal position 

 of the flower fixes the manner of approach. The "wings" 

 guide the insect in entering the flower to seek the honey, 

 which lies on the inner side of the bases of the filaments. 

 The mechanism for dusting the bee with pollen varies in 

 different species. In the Clovers and others the weight 

 of the bee causes the stamens and stigma to slide forward 

 out of the keel, the stamens depositing pollen on the 

 underside of the bee's body, while the Stigma takes up 

 pollen that may be adhering there in consequence of 

 previous visits to other flowers. In the Genistas, Medicks, 

 and Broom, the keel more tightly confines the stamens and 

 pistil, which rupture the keel with explosive force on 

 pressure jiroduced by a bee's visit, dusting the insect with 

 pollen. In Rest-harrow, Lady's-fingers, &c., there is a kind 

 of piston mechanism, the stigma sliding forward and 

 pushing out against the bee's body a small quantity of the 

 pollen, which is shed by the stamens, and collects in the 

 forward end of the keel. Finally, in Vetches, Vetchlings, 

 Ac, the style bears a brush of hairs, which similarly 

 sweeps the pollen out of the keel against the body of a 

 visiting bee. In the Broom, half the stamens are shorter 

 than the others. When a bee alights on the flower, first 

 the short stamens explode out of the keel, dusting the 

 underside of the insect ; then the long stamens spring 

 out, and shed their pollen on the bee's back. 



When the flower is fertilized, the ovary grows, and 

 develops into the pod, which is so characteristic and well- 

 known. In some genera, such as the Clovers, the 

 petals do not fall, but remain, brown and dry, cover- 

 ing the short fruit ; but in the more conspicuous 

 cases the pod is long and bare. These pods have in 

 many cases a pecviliar method of sudden rupture, 

 and consequent scattering of the seeds wliich they 

 contain. When the seed is ripe, as the pod dries, 

 certain strong-walled cells which run diagonally 

 across each valve of the pod contract spirally, 

 causing a torsion which eventually ruptures the pod 

 with violence, each valve twisting spirally, and fling- 

 ing the seeds to a distance. The burst pods of Lotus 

 cornicidatus will be found to have each valve twisted 

 by several convolutions ; and on a hot summer's 

 day, amid a grove of Gorse the air is sometimes 

 filled with the cracking of the jwds as they explode. 

 The seeds contained in these explosive pods are 

 often com])aratively heavy, the embryo being set 

 between two amiile pads of food-material ; nevertheless , 



of dispersal is adopted by many of the Medicks. The pod 

 is curiously modified, being curled up in y close spiral, and 

 furnished with numerous conspicuouiy^rved spBfces. The 

 spines cause the pods to becom^ attach^ ffei^«assing 

 animals —probably to their feelM^r ■fSe pj*^ grow low 

 on the ground— and thus Ujeyljapom^'fQely^ispersed. 



Finally, we may bri^^..jjSss, inf^>view,vi(jlre various 

 British members of ttfts intere.stjji^ and J^autiful Order 

 of plants. Of the shrubby species, wjg)'«ave the Broom 

 (Cytisiis scoparius), the aply n3riti^jft.Te[)resentative of a 

 well-known Old Worldpfi?i"iQs. ^^Uorse there are three 

 closely allied species (fVrr , n-^neas, U. nanus, U. Gallii). 

 The first occurs throughout our Islands, the second 

 chiefly in the south of England, the third mostly in the 

 west and in Ireland. Of the three Genistas (G. tinctoria. 

 G. amiJicii, and G. pilosa), the fij-st two range through 

 England into Scotland, the third being a local southern 

 English plant ; all are absent from Ireland. Of Kest- 

 Harrow (Ononis), there are likewise three species, of 

 which two are wide-spread, the third, 0. reclinata, being a 

 small southern annual. The little Fenugreek (Trigonella 

 purpurascens) is an anomalous plant that has had a 

 temporary home in many genera ; it is very local in 

 distribution. The native Medicks are six in number, and 

 show a great variation in their pods, which may be bxre 

 and nearlv straight, or curled into a close ball and densel.y 

 spiny. They are plants of dry places and waste ground, 

 and have their head-quarters in south-eastern England, 

 like most genera of similar proclivities. Of the pretty 

 Melilots, only one species, M. officinalis, is reckoned native, 

 but several others have colonized our coimtrv, or appear 

 as ballast plants The Trefoils (Trifolium) are the 

 largest British genus of the Order, numbering eighteen 

 native species, and half-a-dozen others more or less 

 thoroughly established. Some of these, such as the well- 

 known Red Clover (T. pratense) and Dutch Clover 

 (T. repeus), are valuable meadow plants ; most of the 

 others favour light soils or sandy ground. One, the 



Fia. 5 



-Strawberry -Headed Clover (Trifolium fragiferiim). 

 1 , X \; 'i, imtural size ; 3, x 2. 



Via. ^. — Fruit oC Reticulated lledick, J/ti/iVai^o rtrtfii/aio. x 3. 



they are ejected to a considerable distance, and the seed- 

 lings grow up clear of the parent plant. A different mode 



curious Strawberry-headed Clover (r./)-a</i/t'/-H«(), chooses 

 salt mai'shes ; the fruiting heads of this species are 

 rendered conspicuous by the way in which each calyx is 

 inflated. Of Lady's-fingers (Anthijllis). the only British 

 .spi'cies is the woU-known and widespread A. Vidneraria. 

 Lolit.<, >r liird's-foot Trefoil, numbers five species, of 

 whicli llic rarest are L. mnjndissinius and L. hispidus, 

 both confined tn the south of England. The most familiar 

 is the di'lightful little L. corniculatus, which adorns diy 

 banks, especially near the sea, with its elegant glaucous 

 foliage and umbel-like clusters of fragrant yellow blossoms. 



