VI INTRODUCTION TO BOTANY. 



called ribs or nerves ; the smaller branches then retaining the names veim 

 or veinlets. When one principal nerve runs direct from the stalk towards 

 the apex of the leaf, it is called the midrib. When several start from the 

 stalk, diverge slightly without branching, and converge again towards the 

 summit, they are said to heparalfel, although not mathematically so. The 

 venation is said to be reticulate or netted, when the veins and veinlets are 

 inosculated together like the meshes of a net ; such veins are said to 

 anastomose together, 



40. The lobes, segments, or leaflets of leaves are, 



pinnate, when several succeed each other on each side of the midrib or 

 common petiole (compared to the branches of a feather). A 

 pinnately-lobed leaf is called pinnatifd. A pinnately-lobed or 

 divided leaf is called lyrate, when the terminable lobe or segment 

 is very much larger and broader than the lateral ones ; runcinate^ 

 when the lateral lobes are curved backwards towards the base 

 of the leaf; pecti)Mte, when the lobes resemble the teeth of a 

 comb. 



palmate or digitate, when several diverge fi'om the same point ; com- 

 pared to the fingers of a hand. A leaf with palmate lobes is 

 called iHilmatiJid. 



ternate, when three only start from the same point. A leaf with 

 temate lobes is called trijid. Alcaf with 3 leaflets, like a trefoil, 

 is trifoUoIate ; and when the common petiole is prolonged beyond 

 the insei-tion of the lateral leaflets, carrjong forward the terminal 

 one a short distance, it is pinnately trifoliolate or unijugate. 



pedate, when the di\dsion is at first temate, but the two outer branches 

 are forked, the outer one of each fork again forked, and so on, 

 and all the branches start fi'om near the base ; vaguely compared 

 to the foot of a bird. A leaf with pedate lobes is called pedatifid. 



41. The teeth, lobes, segments, or leaflets may be again and again 

 toothed, lobed, divided, or compoimded. Some leaves are 3-4 or many 

 times divided or compounded. In the latter case they are termed 

 decompound. 



42. The number of leaves, or of their parts, is expressed adjectively by 

 the following numerals, derived from the Latin : — 



uni-, bi-, tri-, quadri-, quinque-, sex-, septem-, octo-, novem-, decern-, miilti-, 

 1-, 2-, 3-, 4-, 5-, 6-, 7-, 8-, 9-, 10-, many-, 



prefixed to a termination, indicating the part referred to. 

 Thus, 



xinidentate, bidentate, midtidentate, mean 1-toothed, 2-toothed, many- 

 toothed. 



bijid, trijid, mnUijid : — 2-lobed, 3-lobed, many-lobed. 



unifoliolate, bifoliolate : — with one leaflet, with two leaflets, etc. 



wiijugate, bijugate, mnltijugate, with one, two, or many paii-a of 

 pinnce, or leaflets of a pinnate leaf. 



bipinnate, tripinnate, etc., twice pinnate, thrice pinnate. 



biternate, triternate, twice temate, thrice temate. 



43. Leaves, or their parts or any other flat organs of plants are, 



linear, when long and narrow, at least 4-5 times as long as broad, 



with two margins nearly parallel ; 

 subidate, or awl-shaped, when long and narrow, tapering to a sharp 



point ; pungent, when the point is rigid and piercing. 

 lanceolate, v/hen three or more times as long as broad, broadest just 



below the middle, and tapering towards the summit ; 

 ctmeate, when broadest above the middle, blimt at the apex, and 



tapering to the base ; compared to an inverted wedge ; fabelli- 



form or fan-shaped, is broadly cime;ite and roimded at top. 



