ELEMENTARY BOTANY. 



246. In those Floras where analytical tables are not given, the student is usually 

 guided to the most important or prominent characters of each genus or species, either 

 by a general summary prefixed to the genera of an Order or to the species of the 

 genus, for all such genera or species ; or by a special summary immediately preceding 

 the detailed description of each genus or species. In the latter case this summary is 

 called a diagnosis. Or sometimes the important characters are only indicated by 

 italicizing them in the detailed description. 



247. It may also happen that the specimen gathered may present some occasional 

 or accidental anomalies peculiar to that single one, or to a very few individuals, which 

 may prevent the species from being at once recognized by its technical characters. It 

 may be useful here to point out a few of these anomalies which the botanist may be 

 most likely to meet with. For this purpose we may divide them into two classes, viz. : 



(1.) Aberrations from the ordinary type or appearance of a species for which some 

 general cause may be assigned. 



A bright, light, and open situation, particularly at considerable elevations above the 

 «ea, or at high latitudes, without too much wet or drought, tends to increase the size 

 and heighten the colour of flowers, in proportion to the stature and foliage of the 



Shade, on the contrary, especially if accompanied by richness of soil and sufficient 

 moisture, tends to increase the foliage and draw up the stem, but to diminish the num- 



A I" 6 ' 8 ° d colour of the flowers. 



A hot climate and dry situation tend to increase the hairs, prickles, and other pro- 

 tractions of the epidermis, to shorten and stiffen the branches, rendering thorny plants 

 yet more spinous. Moisture in a rich soil has a contrary effect. 



■the neighbourhood of the sea, or a saline soil or atmosphere, imparts a thicker and 

 more succulent consistence to the foliage and almost every part of the plant, and ap- 

 pears not unfrequently to enable plants usually annual to live through the winter. 



2T er ? in a maritime variety are often much fewer, but not smaller. 



■the luxuriance of plants growing in a rich soil, and the dwarf stunted character of 



nose crowded in poor soils, are too well known to need particularizing. It is also an 



Teryday observation how gradually the specimens of a species become dwarf and 



unted as we advance into the cold damp regions of the summits of high mountam- 



tenp 8 ' ° r mt ° high northern latitudes ; and yet it is frequently from the want of at- 



ntion to these circumstances that numbers of false species have been added to our 



numerations and Floras. Luxuriance entails not only increase of size to the whole 



v nc,or ot particular parts, but increase of number in branches, in leaves, or leaflets 



a compound leaf; or it may diminish the hairiness of the plant, induce thorns to 

 S^7 out mto branches, etc. 



^Psules which, while growing, lie close upon the ground, will often become larger, 

 e succulent, and less readily dehiscent, than those which are not so exposed to the 

 m <gture of the soil. ' 



twwl ea i en down bv shee P or cattle, or crushed underfoot, or otherwise checked in 

 circmf? ' 0r tree " or sh ™ bs cut down to the ground, if then exposed to favourable 

 in thT C CS ° f 80il and climate, will send up luxuriant side-shoots, often so different 

 cocrr,;! vT™, * their leaves, in their ramification and inflorescence, as to be scarcely re- 



Anrf i F the same s P ec »es- , u 



»erv £* Whlch have germinated in spring, and flowered without check, will often be 

 later ^T* m a8 P ect from individuals of the same species, which, having germinated 

 follow,^ Bto PP ed b y summer droughts or the approach of winter, and only flower the 

 nmials KM ° n upon a 8econd growth. The latter have often been mistaken for per- 



•noi^ 8 ' or cr088es between two distinct species, come under the same category of 

 ftev «* 8 'g^imens from a known cause. Frequent as they are in gardens, where 

 m i tW» • Clall y Produced, they are probably rare in nature, although on this suD- 

 «WSL£. m,wh diy ersity of opinion, some believing them to be very frequent, others 

 of ER&? their existence. Absolute proof of the origin of a plant •*■£*■ 

 *«<*alw.> 1IlnpOBsible i but ifc is P rett y generally agreed that the following particulars 

 alwa Js co-exist in a wild hybrid It partakeTof the characters of its tiro parent. : 



