Vlll INTEODUCTION TO BOTANY. 



is structurally a cordate "or reniform leaf whose auricles are confluent ; 

 just as a perfoliate leaf (35) is the amplexicaul, in a similar condition. 



50. In their consistence, leaves or other flat organs are, 



fleshy^ when thick and soft ; succulent is generally applied in the 

 same sense, hut implies the presence of more juice ; 



coriaceo7(s, or leather}^, when fiiTn and dry, or very tough ; 



membranous, when thin and not stiflF; 



scarious, or scariose, when very thin, more or less transparent, and 

 not green, yet rather stifi". 



51. Solid leaves (or stems, fruits, seeds, or other parts of plants not 

 flattened) are, 



acerose, or aciciilar, very slender, like needles ; 



setaceous, bristleform ; capillary, when verj'" slender, like hairs; 



ovoid, when egg-shaped, ■v\'ith the broad end downwards ; ohovoid, 

 . if the broad end be upwards. 



globular, or spherical, round like a ball ; 



conical, cone-shaped, tapering upwards ; and o^c?o«/m?, tapering down- 

 wards, if in both cases a cross-section shows a circle. 



pyramidal, when tapering upwards, obpyramidal, when tapering 

 downwards, if in both cases a cross-section shows a triangle or 

 polygon. 



fusiform, when broad in the middle and tapering to each end like a 

 spindle, and not angular. 



cylindrical, when not perceptibly tapering and not angular. 



terete, cylindrical, ^dth the cross-section circular ; 



moniliform, and torulose, when terete and consti'icted at intervals. 



trigonous, rather bluntly 3-angled ; triquetrous, sharply 3-angled. 



flattened, or depressed, when vertically compressed. 



compressed, when laterally flattened ; and obcompressed (a bad term) 

 sometimes used in the sense of dorsally compressed. 



meniscoid, shaped like a watch-glass. 



patelliform, saucer-shaped. 



52. The mode in which unexpanded leaves are disposed in the leafbud 

 is called their vernation, or prafoliation : it varies considerably, but is 

 rarely noticed in descriptive botany. 



§ 6. Stipules. 



53. Stipules are leaf -like or scale-like appendages at the base of the 

 leafstalk or on the node of the stem. They are' often absent, when the 

 leaf is exstipulate ; when present they are generally two, one at each side 

 of the petiole, and they sometimes appear to protect the young leaf before 

 it is developed. They vary extremely in size and appearance ; and are 

 either free, i. e. separate fi^om the petiole, or adnate, i. e. laterally attached 

 wholly or in part to the petiole. They often afford excellent characters 

 in distinguishing plants from each other, and ought always to be closely 

 observed. 



54. Stipellce, or secondary stiprdes, ar esimilar organs, sometimes found 

 on compound leaves at the points where the leaflets are inserted. 



§ 7. Bracts. 



55. A Bractea or bract, is either the leaf from the axil of which a flower 

 is developed, when this differs in appearance from an ordinary leaf; or 

 else it is any reduced leaf situated on the branches of the inflorescence (57) 

 below the calyx. 



56. When flower-stalks are branched, and have bracts at their first as 

 well as at their second and subsequent ramifications, the former are called 

 general, the liitter partial bracts, or bracteolcs. The tenus general and 



