48 PLANTS: THEIR NATURAL GROWTH 



in the two extremes, one passes by these gradations of form so imperceptibly into the other 

 as to forbid the idea of any specific difference. The following are the leading characteristics, 

 such features as would strike the ordinarily careful observer, ignoring as foreign to our present aim 

 more refined differences of structure : — In the C. nigra, var. genuina, the branches are short and 

 much thickened beneath the flower heads, the florets all equal and in a compact head ; in the 

 C. nigra, var. decipiens, the branches are slender and thicken but very slightly beneath the flower 

 heads, and are less clothed with leaves than in the preceding, while the most marked difference 

 is seen in the flower heads, the latter variety having an outer row of large and radiant florets. 

 The first form is found throughout Britain, and becomes the typical plant in the north, the second 

 variety, though as abundant in many localities as the other, being confined almost entirely to the 

 more southern counties. The upper leaves in both varieties are of very simple form, linear 

 or lanceolate in outline, the lower ones being often (figs. 244, 245) slightly lobed, though in other 

 cases (fig. 246) the leaves merely broaden, and do not throw out any lateral lobes. The Centaurea 

 genus derives its name from a belief in its medicinal effects that was firmly held throughout the 

 middle ages, it being fabled that the Centaur Chiron cured himself, by means of one of these 

 plants, of a wound inflicted by Hercules. Country people give them many expressive names, as 

 in some places they are called Hurt-sickles, from their tough and wiry nature, while in other 

 localities they are known as Hard-heads or Iron-weeds, in allusion to the very solid mass on which 

 the florets are set. 



The C. Scabiosa, or greater Knapweed (fig. 247), though more local than the Black 

 Knapweed, is not unfrequently found in pastures, hedgerows, and waste ground, thouglj it is rare 

 in Scotland. It is one of the numerous plants that appear to thrive best on the chalk, and in such 

 a district it is generally very commonly to be met with. The whole plant is stouter than the 

 preceding ; the stems attain to a height of some three feet, and are considerably branched. The 

 leaves are firm in texture, and deeply pinnatifid, giving a very rich effect to the plant The 

 lower leaves are very large, so large that press of space has necessitated our representing one of 

 them away from the present plate ; it will be found on plate VI., fig. 66, though even there we have 

 been obliged to considerably reduce it from the natural size. The involucral bracts (fig. 248) are 

 very large, and with a sharply defined black fringe, that gives a markedly ornamental character to 

 the flower-head. It will be noticed that in this species the stem does not thicken beneath the 

 flower-head, nor has it the agroupment of small leaves characteristic of that part in the C. nigra. 



The overlapping or imbrication (Lat. imbrex, a roofing tile) of the bracts of the involucre, 

 bears a strong likeness to what, from its resemblance to fish scales, is known ornamentally as 

 the scale-form. The scale-form is composed of a series of semi-circles, arranged as shewn in figs. 

 218, 347 ; the decorative effect being produced, either, as in those examples, by the filling in of 

 foliate forms, or by variation of colour in the scales themselves. It is one of the earliest 

 ornamental forms and one of the most universal, being found abundantly in every style of 

 decorative design, in the Egyptian paintings some three thousand years old, throughout the 

 Ninevite or Assyrian, Persian, and Chinese styles in Eastern art, and in the Norman, Gothic, and 

 Renaissance periods of Western art, the natural fish scale being doubtless the proto-type. 



PLATE 31. 



" For many years it has been one of my constant regrets that no schoolmaster of mine had a knowledge of natural history, 

 so far, at least, as to have taught me the grasses that grow by the wayside, and the little winged and wingless neighbours that are 

 continually meeting me with a salutation which I cannot answer, as things are. Why didn't somebody teach me the constellations 

 ioo, and make me at home in the starry heavens that are always overhead, and which I don't half know to this day .' I love to pro- 

 phesy that there will come a time when, not in Edinburgh only, but in all Scottish and European towns and villages, the schoolmaster 

 will be strictly required to possess these two capabilities (neither Greek noi Latin more strict), and that no ingenuous little denizen 

 of this universe be thenceforward debarred from his right of liberty in those two departments, and doomed to look on them as if 

 across grated fences all his life." — Carlyle. 



The Agrimony (Agrimonia Eupatoria), the subject of the present plate, is very commonly 

 distributed throughout England and Ireland, and more sparingly met with in Scotland. It 

 flowers throughout the Summer months. From the smallness of the blossoms, it is a plant that 

 may easily be overlooked in the masses of undergrowth found in the hedgerows, its favourite 

 habitat. Though subject to much variation, both in size and form, it is ordinarily from eighteen 

 inches to two feet high. The plants vary in the hairiness of the foliage and stem, in the 

 form of the calyx and the size of the flowers, hence some botanists have been prepared 

 to divide the present into one or more sub-species, or even to give to some a distinct specific 

 claim, but the differences do not appear sufficiently marked nor constant enough to justify 

 their being considered more than accidental variations from the typical form. The yellow 



