Mabcii, 1903. 



KNOWLEDGE. 



67 



such puzzling series among their species. Apparently, in 

 Bnhus the innate power of variation is being exercised to a 

 high degree, and could we look forward, we might expect 

 to find that by a further divergence along the present lines 

 of variation, and a su])pression of the intermediates, a 

 group of well-marked species might ultimately arise from 

 Rub us fndieosus. 



Closely allied to Riibiis is Ffagnn'a, the Strawberry, as 

 valuable to us as the Raspberry on account of its delicious 

 fruit, fhe difference in the appearance of the fruit of 

 these two genera is due to the fact that whereas in the 

 Raspberry the edible fruit is formed by a number of soft 

 juicy carpels set on a comparatively bard receptacle, in the 

 Strawberry the carpels are dry, and the receptacle on 

 which they are set swells up and becomes sweet, juicy, and 

 coloured. The little Wood Strawberry (F. vesca) is our 

 only native species. The luscious fruit of our gardens 

 is due to the (ailtivation of the Haiitbois Strawberry 

 (F. t'hiti'ir). a plant chiclly of eastern Europe. The well- 

 known ami prrtty Potcntillas cipiik' next in order. Including 

 Sihijiililiii, Tonnnifillii, itnd Cmihi nun, which are sometimes 

 reckoned distinct genera, the British species number twelve, 

 all but one perennial hei-bs. Many of these are familar 

 wild-flowers — the favourite Silverwoed (P. Anserina), the 

 Creeping Cinquefoil (P. repfans), the Tormentil (P. 

 Torinenlilla), all with yellow flowers, and the Strawberry- 

 like P. Fragariastnim, which has white blossoms. The 

 Marsh Cinquefoil (P. palustris) is easily recognised by its 

 upright stems, pinnate leaves, and dull red-brown flowers. 

 Among the rarer species are the Shrubby Cinquefoil (P. 

 fruticosii), a small bushy gregarious shrub, looking in the 

 distance like low Gorse. It is a very local plant, occurrmg 

 in the North of England and the West of Ireland. P. 

 Silibaldi is a little Scotch alpine, with minute yellow 

 flowers. P. alpestris is also alpine, with more conspicuous 

 yellow blossoms. The rai-est British sj)ecies is P. rvpestris, 

 a comparatively tall plant with pinnate leaves and white 

 flowers, found (m limestone rocks in Montgomeryshire. 

 Dri/as has but one British species, the delightful D. 

 (irfdjii-tala. a far-creeping prostrate shrub covei'ing mountain 

 rocks with a sheet of dark-green shining leaves, white 

 underneath, from among which. rise singly the large white 

 blossoms, which give way to clusters of feathery fruits, 

 each achene being furnished with a long awn — the only 

 instance among British Rosacex. of a fruit adapted for 

 wind-dispersal. Of Geum, or Avens, we have two species. 

 G. urbanam is a common wayside plant, growing a couple 

 of feet in height. Its fruits are furnished with long 

 hooked points (the persistent styles) which easily attach 

 themselves to the wool of passing animals, and thus secure 

 for the seeds a wide dispersal. G. rivale, the Water Avens, 

 is generally like the last, but has larger drooping reddish 

 flowers, which do not open widely. 



Tvu'ning now to the I'oterie.v. Three British genera 

 belong here : — Foteriii,i)i. Alrhrinilln, and Agrinionia. The 

 two species of roteriinti, P. officinale (Greater Burnet) 

 and P. Sanguisorba (Lessor Burnet) are well-known 

 English wild-flowers. Both have pretty pinnate leaves, 

 from among which rise slender stems bearing dense egg- 

 shaped heads of small flowers, which are dark p\uple in 

 the former, greenish or purplish in the latter. If the 

 flowers be examined, they will be found to be destitute of 

 corolla. Four coloured j)ointed calyx-segments take the 

 place of petals. In P. Sontfidsorba, moreover, the tlowers 

 are made male or female by the suppression of one or 

 other set of essential organs. Both plants are wind- 

 fertilised, and have the elevated dense inflorescence, 

 inconspicuous blossoms, and conspicuous stamens and 

 j)istils, characteristic of such plants. Alcliemilla supplies 

 us with several pretty herbs. The uomuioa Lady's-mantle 



Fig. 3. —Alpine Lady's-mantle 

 (Alchemilla al/piiia). Half 

 natural size. 



(A. vulgaris), with fan-like leaves and golden-gi-een 



flowers is well known ; and the little A. alpina, frequent 



on our higher mountains, is 



justly a favourite in gardens. 



it is the beautiful silkiness 



of the under-side of the 



leaves that forms its most 



pleasing character. A. ar- 



vcnsii (Parsley Piert), is a 



quaint little annual, common 



in cultivated ground, with 



inconspicuous green flowers. 



In Alcheniilla,iisinPoterium, 



the corolla is absent, but the 



eight-parted calyx, of which 



each alternate segment is 



smaller than its neighbour, 



gives the appearance of a 



four-parted calyx, and a 



four-parted green corolla. In 

 Agrimonia, alone of our 



Poteriese,a. corolla is present. 



The flowers of the Agrimony, 



borne in long spikes, have 



yellow petals. The fruit of 



Agrimony is interesting, 



being furnished round the 



top with a ring of hooked 

 bristles, which like the 

 hooked styles of (rejoff, assist 

 seed-dispersal by becoming entangled in the hair of passing 

 animals — or in one's stockings. Ayrimonia Eupatoria, 

 the common Agrimony, is a well-known roadside wild- 

 flower. A. odorata is vei-y similar, but larger and with 

 more spreading fruit-bristles. 



The Bosem, which consist of the genus Rosa, are distin- 

 guished by their fruit, in which the numerous dry nuts 

 are enclosed by the calyx-tube, which becomes fleshy and 

 coloured, giving the apjiearance, in botanical jJiU-lance, 

 of an inferior fruit. The Roses are prickly shrubs, 

 usually climbing hy means of their hooked prickles. The 

 species are found chiefly in North-Temperate regions. 

 The genus resembles Ruhus in ]iossessing many fonus 

 which approach too close to each other to be satisfactorily 

 treated as species. The number of Roses in our country 

 may be variously estimated at 7 to 13, according to the 

 amount of "splitting" which we arc prepared to indulge 

 in. All have large and showy flowers, and are among 

 the most delightful features of our English hedge-rows. 

 To attempt to discrimiuite the various species in an 

 article of this kind would be futile. The most easily 

 distinguished are the little Burnet Rose {R. gpiitogissinui), 

 perhaps the most deliciously fragrant of our species, and 

 the Trailing Rose (R. arveiisis), whose large white blossoms 

 are almost scentless. 



To come finally to the Pomacejv. Here belong the 

 genera Pi/riis (Apple and Pear), Oratxgitg (Hawthorn), 

 and Cotoiieaster. Of Ptjriig, the best known species is 

 P. Malus, the Crab-Apple, fi-om which the many kinds 

 of cultivated apple are derived. The variety aevrba. which 

 is truly native with us, is a more picturesque shrub, both 

 as regards flower and fohage, than var. mitis, which, 

 though equally common, is believed to have always a gjirdeu 

 origin. The Wild Pear (P. communis) is, like the last, 

 doubtfullv native, though found often in wild ground. Of 

 several other species of Pijrus, the most familiar is the 

 Mountain Ash (P. Aucitparia), which alone of British 

 species jiossesses pinnate leaves. The White Beam 

 (P. Aria), with egg shaped sernite leaves, white and felty 

 on the uuder-side, is also a familiar tree. Turning to the 



