Wmkds ok SoT'i'ii Akrica. 545 



Leaves are divided into sim/ple and coinpoiind leaves. 



The niwqiJc leaf is one whose mai'o-ins are entire or in which the 

 Incisions do not reach down to the niid-ril), e.<4'. llic While Kpeca- 

 ch liana ( Richard Ronid scahni), eic. (See fif^'. .16.) 



Ill a i-oiiipoinul leaf llie Icaf-hlade is cni down io Ihc niid-iih lo 

 form leaHels, e.<^'. Ihe Black .Tack (IJidr7is pilosa). the .Mexican 

 Marit^old (Tagefcs i/ii/iu/a), etc. (See fig. IT.) 



The various types of compound hares are as follows: — 



Pinnate, when the lobes are arranged in a single row on either 



side of the rarhis, e.g. the Mexican Marigidd (Tar/cfes 



//I in. I fa). (See fig. IT.) 

 I'al iiiatel ij cuiiipound leaf is one in which ihc leaileis arise at 



one point at ihe apex of the petiole, and spread out in a 



fan-like mannei'. e.g. Dagga (Cainiah/s safica). (See fig. 



., . ^^-^ 



7 n foliate, when the leaf has three leaflets, e.g. ]\Ielilot 



{Melilotus parvifiora), etc. (See fig. li).) 



vSimple leaves or the leaflets of compound leaves may be of various 

 shapes : — 



Linear, when the leaf is about sis times h)nger than broad, 



e.g. the upper leaves of the False Horse Weed iKrn/cron 



ho/iarie))sis), etc. (See fig. 20.) 

 Ohloncj, when the leaf is two-three times h)ngei- than broad. 



(See fig. 21.) 

 Lanceolate, when the leaves are narrow and taj^er at each end, 



e.g. the Eibgrass (Plantarjo lanceolafu). (See fig. 22.) 

 Elliptic, when the leaves are shaped like an ellipse. (See fig. 



23.) 

 Ovate, when the leaf is broader at the base than at apex, e.g. 



the Common Chick Weed (Stellar ia media). (See fig. 24.) 

 Ohovate is opposite to ovate, Avhen the ap(^x is broader than 



the base. (vSee fig. 25.) 

 Spatliulate, when the leaf is shaped like a spoon ; the apex is 



rounded. (See fig. 26.) 

 Palmate, when the leaf is lobed or divided so tliat the sinuses 



point to the apex of the petiole, e.g. the ^[allow (Malva 



rotnndi folia), the Castor ( )il (Ricinas cttnninniis), etc. 



(See fig. 2T.) 

 Leaves are differently shaped at the apex, the base, and the 

 margins are often lobed as follows: — 



Acute, when the leaf ends in a sharp point. (See fig. 28.) 

 Obtuse, when the apex is blunt, e.g. Hare's Ear Mustard 



(Corungia orientale, L.). (See fig. 29.) 

 Truncate, when the apex of the leaf is square. (See fig. 3t).) 

 Acuminate, the apex of the leaf is prolonged into a tapering 



point. (vSee fig. 31.) 

 Aristate, when the apex is tipped with a bristle-like point. 



(See fig. 32.) 

 Mucronate, when the apex of the leaf is tipped with a small 



or short point. (See fig. 33.) 

 Cordate, Avlien the leaf is heart-sliaped. (See fig. 34.) 

 Cuneate, when the leaf is Avedge-shaped at the base, e.g. 



Purslane (Port)ilaco oleracea). (See fig. 35.) 

 IS 



