

VI 



OUTLINES OF 



I 



perfoliate, wteu the base of tlie blade not only clasps the stem but closes round 

 it on the opi>osite side, so that the stem appears to pierce through the blade. 



decurr^nt, when the edges of the leaf are continued down the stem so as to torm 



raised lines or narrow appendages, called wings. ^^4.;nlp 



sheathinr;, when the base of the blade, or of the more or less expanded petiole. . 

 fonus a vertical sheath round the stem for some distance above the node. 



38. Leaves and flowers are called radical, when inserted on a rhizome or stocK, 

 or so close to the base of the stem as to appear to proceed from the root, riiizome, 

 or stock ; cauline, when inserted on a distinct stem. Radical leaves are rosutate 

 when they spreatl in a circle on the ground. 



39. Iieaves are , , „-nn*n 

 simple and entire, when the blade consists of a single piece, with tlie margin 



nowhere indented, simple being used in opposition to compound, entire m opposition 



to dentate^ loled, or divided. ^ ^ 



ciliote, when bordered with thick hairs or fine hair-like teeth. ^ i x i, 



dentate or toothed, when the margin is only cut a little way in, into what Have 

 been compared to teeth. Such leaves are serrate, when the teeth are regular ana 

 pointed like the teeth of a saw ; crenate, when regular and blunt or rounded (com- 

 pared to the battlements of a tower) ; serrulate, and crenulate, when the serratures 

 or crenatures are small ; sinuate, when the teeth are broad, not 'deep, and irregular 

 (compared to bays of the coast) ; wavy or undulate, when the edges are not Hat, 

 but bout up and down (compared to the waves of the sea). , , . 



lobid or cleft, when more deeply indented or divided, but so that the incisions 

 do not reach the midrib or petiole. The portions thus divided take the name ot 

 lobes. When the lobes are narrow and very irregular, the leaves are said to be loci- 

 niate. The sjxices between the teeth or lobes are called sinuses. 



divided or dissected, when the incisions reach the midrib or petiole, but the 

 parts so divided off, called segments, do not separate from the petiole, even when 



the leaf falls, without tearing, . i j ff 



compound, when divided to the midrib or petiole, and the parts so divided ott^ 

 called UaHets, separate, at least at the fall of the leaf, from the petiole, as the whole 

 \Gk\{ does from the stem, without tearing. The common stalk ni)on which the leaf- 

 lets are inserted is called the common petiole or the rhachis ; the separate stalk or 



each leaflet is s^petiolule. ... it_ 



40. Leaves are more or less marked by veins, which, starting from the stalk, 

 diverge or branch as the blade widens, and spread all over it more or less visibly. 

 The principal ones, when prominent, are often called ribs or nerves, the smaller 

 branches only then retaining the name of veins, or the latter are termed veinlets. 

 The smaller veins are often connected together like the meshes of a net, they are 

 then said to anastomose, and the leaf is said to be reticulate or net-veined. When one 

 principal vein runs direct from the stalk towards the summit of the leaf, it is called 

 the vndrib. When several start from the stalk, diverge slic^htly without branching, 

 and converge again towaids the summit, they are said to be parallel, although not 

 mathematically so. When 3 or 5 or more ribs or nerves diverge from the base, the 



nerved 



etc. The 



^ - - - ^ 9 $ 



mitlrib a little alx)ve the base, the leaf is, triplino'ved, quintuplino^ve 

 arrangement of the veins of a leaf is called their venation, 



41. The Iieafiets, Segments, Iiobes, or Veins of leaves are 

 jiinnate (feathered), when there are several succeeding each other on each side 

 of the midrib or petiole, compared to the branches of a feather. A pinnately lobed 

 or divided leaf is called lyrate when the terminal lobe or segment is much larger 

 and broader than the lateral ones, compared, by a stretch of imagination, to a lyre ; 

 runcinatc, when the lateral lobes are curved backwards towards the base of the leaf ; 

 pectinate, wlien the lateral lobes are numerous, narrow, and regular, like the teeth 



of a comb. 



palmate or digitate, when several diverge from the same point, compared to the 



fingers of the hand. V 



tenuite, when three only start from the same point, in which case the distinc- 

 tion between the Dalmate and pinnate arrangement often ceases, or can only be 





k ^ 





J' 



