BOTANY. 



stance, juicy when young 1 , extending 

 from the roots to the summits of the 

 branches. In some plants, as grasses, it 

 is hollow, merely lining the stem. Lin- 

 naeus believed this part to be analogous 

 to the nerves of animals, and the in-.me- 

 diate cause of the growth and evolution of 

 all their parts ; that it was always strug- 

 gling, as it were, to overcome the re- 

 sisunce of their woody substance, and 

 that it did accordingly elongate itself, and 

 cause the increase ot the vegetable body 

 in young and tender parts, where that 

 resistance is least. The formation of 

 seeds he conceived only put a final stop 

 to its extension by the production of off- 

 spring from it. Facts are not wanting in 

 support of this hypothesis ; but there are 

 many more conclusive ones against it. 

 The real use and physiology of the part 

 in question still remains in great ob- 

 scurity. 



OF ROOTS. 



In defining the parts of vegetables, it 

 is found most commodious to begin from 

 the bottom, proceeding upwards. Hence 

 the root t which is the first part pro- 

 duced by a germinating embryo, comes 

 first under consideration. Us presence 

 seems necessary to plants, as it serves 

 to fix and hold them in the earth, from 

 which they imbibe nourishment through 

 their elementary tubes. Sea-weeds, how- 

 ever, afford an exception to this, for they 

 are nourished by their surface, the root 

 serving only to fix them to a convenient 

 spot. 



A root is either annual, biennial, or pe- 

 rennial. The first kind live but one sea- 

 son, as barley; the second survive one 

 winter, and perish at the end of the fol- 

 lowing summer, after perfecting their 

 seed, like wheat ; if, however, any cir- 

 cumstances should prevent their flower- 

 ing, they may live several years till that 

 event takes place. Perennial roots are 

 such as remain and produce blossoms for 

 an indefinite term of years, like those of 

 trees and shrubs in general, and of many 

 herbaceous plants whose stems are an- 

 nual. 



The body of the root is denominated 

 eaudex the fibrous, which is the only 

 essc-ntial part, radicnla. This latter is 

 strictly annual in all cases, and is what 

 serves for absorbing the nutritious fluids 

 of the soil. It is necessary for the bota- 

 nist, as well as the farmer and gardener, 

 to be well acquainted with the several 

 kinds of roots, which differ material :> 

 their nature and functions. Those of 



a fleshy nature most powerfully resist 

 drought, and are, as Dr. Smith has sug- 

 gested, reservoirs of the vital energy of 

 the vegetable. We have, with the per- 

 mission of this gentleman, adopted in the 

 following pages those leading ideas upon 

 the subject before us, which are detailed 

 and exemplified more at length in his 

 " Introduction to Physiological and Sys- 

 tematical Botany," to which work we 

 must refer those of our readers, who wish 

 for more deep information than our limits 

 will allow. 



Roots are distinguished as follows: 



1st. A fibrous root, radix fbrosa, con- 

 sists entirely of fibres, as in many grasses, 

 and a number of annual herbaceous 

 plants. These can but ill bear a continu- 

 ed deprivation of moisture or nourish- 

 ment. The fibres carry what they absorb 

 directly to the base of the stem. Botany, 

 Plate 1. fig. 1. 



2nd. A creeping root, repens, is a sort 

 of subterraneous stem, spreading hori- 

 zontally in the ground, throwing out 

 abundance of fibres, as in mint and couch- 

 grass. Weeds furnished with such a root 

 are amongst the most pernicious, being so 

 difficult to eradicate. Nature, however, 

 having furnished them with so powerful a 

 mode of increase, is very sparing in the 

 production of their seeds. Fig. 2. 



3rd. A spindle-shaped root, fnsiformis, 

 is common in biennial plants, though not 

 confined to them. The radish and carrot 

 have spindle-shaped roots, producing nu- 

 merous fibres for the absorption of nutri- 

 ment. Such roots may be transplanted 

 with great safety in the torpid season of 

 the year. Fig. 3. 



4th. An abrupt or stumped root, pr<s-> 

 morsa, like that of the primrose, is as it 

 were bitten off'; hence many plants fur- 

 nished with it have obtained the whimsi- 

 cal name of devil's-bit. Fig. 4. 



5th. A tuberous or knobbed root, tnbe- 

 rosa, a very important sort, appears under 

 a great diversity of forms. In the potatoe 

 it consists of fleshy knobs connected by. 

 common stalks or fibres ; these knobs are 

 biennial, formed in the course of one sea- 

 son, and destined to produce fresh plants 

 the following year. This is the case with 

 the oval or hand-shaped roots of the 

 orchis tribe. Some herbs, indeed, have 

 perennial knobs to their roots. Fig 5. 



6th. A bulbous root, bulbosa, consists of 

 a kind of subterraneous bud, being either 

 solid, as in the crocus ; tunicate, as in the 

 onion ; or scaly, like that of the lily. 

 Fig. 6. These roots, like the knobs 

 ab'Ae mentioned, are reservoirs of nou- 

 rishment, or rather of the vital powers,, 



