897 



will attain a much larger size; also can be conveniently 

 left in the trench with slight protection, anil talien there- 

 from for winter use. Care must be taken not to cover 

 too early, as they decay easily, beginning at the end of 



the foliage; this destroys their appearance. The har 

 dier liinds are used for this purpose and will blinch 

 yellow down to the so-called stem, which is white to the 

 root. Leeks planted out in May are ready for use in 

 September; the sowings can be made earlier and later 

 to suit the time of maturing, and can be sown in 

 August and September in coldframes and wintered 

 over with slight protection, then transplanted to 

 the open ground in April. The varieties best 

 known to American gardeners are London Flig 

 Large Musselburgh or Scotch Flag, Giant Caren 

 tan, and Large Rouen. j. Qtto Thilow 



LEGUMES. The popular name given to a vast 

 and important family of plants, of which pea 

 beau, clover, vetch, etc., are common representa 

 tives. The order is generally known as the pulse 

 family, or Lerjuminosa. It contains nearly 450 

 genera, comprising over 7,000 species, and m 

 economic importance ranks second only to the grassf 

 (Graminecej. The species of this family are distn 



species are widely cultivated as 

 agricultural crops. Among these, beau's and peas are 

 important food-plants, while clover, vetches, peas, meli- 

 lot, alfalfa, lucerne, cow-peas, etc., are valuable forage 

 crops, cover-crops, and green manures. Many of the 

 exotic species are of commercial importance. ' The ar- 

 boreal forms furnish structural timber and cabinet 

 woods. Many also furnish dye-stuffs, rubber, balsams, 

 oils, etc., and some are cultivated for ornamental pur- 

 poses. 



In respect to the character of the flowers, the family is 

 divided into three subfamilies In the large subdivision 

 to which the ornamental species of Mimosa ind Acacia 

 belong the flowers are sniill and legular and often 

 clustered in sphericil ii II n_ b( il The stamens 

 are free or united inti> i tnl m I inu h f\erted In the 

 second subfamilv the ri hi i u u ll\ u regular with 

 the upper petal folded mil 1 ihi ihiis in the bud. 

 The coffee tree honeyl lu r m 1 tli lii^ genus Cassia 

 belong m this subdivision M t t tin n itn e spmesof 



buted over the entire earth. By far the greater number 

 are herbs and half-shrubby plants, but in the warmer 

 regions of the earth they attain the dimensions of for- 



leguminous pod— Daubentonia 



over the others in the bud ' 

 ted below the banner, are 



lower pair, which are sometimes united, form the keel, k. 

 The keel encloses the stamens and pistil, the latter being 

 often bent at right angles to the ovary, or coiled. The 

 stamens are either free or they form a tubular sheath 

 surrounding the ovary. Often the upper one alone is 

 free, leaving a slit along the upper side of the sheath 

 (Fig. 12.55). These flowers are often dependent on in- 

 sects for pollination, a fact which is of great importance 

 in raising clover seed. 



The fruit of the Leguminosse is a pod or Legume, as 

 in the bean (Fig. 1256). As a rule, the pods are one- 

 loculed, and have the seeds arranged in rows. In some 

 tribes they become several-celled by partitions which 

 arise between the seeds. These pods become constricted 

 at the partitions, and at maturity separate into short 

 joints (see Fig. 694, Vol. I). The valves of the pods are 

 generally papery or leathery, and open at maturity, often 

 by a sudden snapping of the valves, which scatters the 

 seeds. In other tribes, however, the pods are indehiscent, 

 or do not split at maturity (Pig. 1257). 



The roots of Legumes have numerous small tubercles 

 scattered throughout the root-systems. Fig. 1258. These 

 are caused by and infested with minute organisms, to 

 which the name bacteroids has been applied. The bac- 

 teroids are always present, and probably multiply to 

 some extent in soils where Legumes have been grown. 

 They are very minute bodies, which are either rod-like in 

 form or branched in the form of a Y or a T. The infec- 

 tion of the plants has been observed to take place 

 through the root-hairs. Within the plant the bacteroids 

 assume a new and peculiar form. They grow out into a 

 branched and flexuous thread, which is enlarged and 

 nodulose at places. At the point of infection the root- 

 cells are stimulated to growth, producing the nodules 

 clKiiM.t.ri-tic of Legumes. The threads permeate the 

 .iitir.' tnlHivl,.. The old threads finally disorganize, 

 :iii.l It i~ Lilieved that their protein substances are 

 uhsorbtd l.v the host. 



