HARDWICKE'S SCIENCE-GOSSIP. 



173 



BOTANICAL WORK FOR AUGUST. 



UNNOTICED DIFFERENCES IN OUR COMMON 

 PLANTS. 



WITH the exception of chickweed, we have few 

 plants so common as the groundsel {Senecio) 

 and the dandelion [Taraxacum). These are our 

 favourites, at least favourites for all bird fanciers, for 

 they can be met with at every season of the year, but, 

 like most other things which are of frequent occur- 

 rence, they are liable to be overlooked by the busy 

 student. Let us, however, bestow a passing thought 

 on these universal species ; they assume so many 

 forms and shapes as sometimes to be unrecognis- 

 able, except to the prying botanist who has often cast 

 a scrutinising glance upon them. 



Common groundsel {Senecio vulgaris (L.). We 

 think it not needful to enter into a full description of 

 this well-known species. Many of our readers must 

 have noticed several well-marked forms ; it is to these 

 we wish to direct attention. 



The type "vulgaris — proper" is about I foot high, 

 often much branched, withpinnatifid, coarsely- toothed, 

 and succulent leaves. 



Sir J. E. Smith describes a species, S. lividus, as 

 closely allied to another species, S. sylvaticus (Linn.). 

 This, however, never has auricles with the leaves ; our 

 first variation from the above type should bear this 

 name : 



Var. 1. Senecio lividus (Sm.). A much smaller plant 

 than the type, with slender stem, and narrow leaves ; 

 very often the flowers are solitary, although we 

 commonly find it with about five. 



2. S. vulgaris (var. \J/). This is a remarkable plant, 

 which appears to have escaped the attention of the 

 authors of our "Floras." The leaves are all entire, 

 lanceolate and with linear auricles. The plant has 

 the resemblance of S. sylvaticus at a distance. It 

 occurs near Penrith, also in several places along the 

 banks of the river Eden. 



3. 6". vulgaris (var. /3). A very luxuriant form of 

 the groundsel, occurs on rich loamy soils ; the leaves 

 are broad, dark green, sometimes almost pinnate ; we 

 however, believe this is not permanent. The variety 

 is certainly reliable, for it comes true from seed. May 

 we beg our botanical collectors to keep one eye open 

 during their rambles for the Senecio. 



The poor dandelion has been more highly honoured, 

 for it has had as many names almost as a Spanish 

 grandee ; here it is known as Taraxacum, there we 

 see it Leontodon. In the " Student's Flora " the older 

 name is used, Taraxacum officinale (Wig.). No 

 common species yields so many varieties as this ; 

 for example we find : 



1. T. Dens-leonis (Desf.). Leaves bright green, 

 broadly runcinate, outer bracts of the involucre 

 recurved. 



2. T. erythrospermum (Andr.). Leaves dark green, 

 often glaucous, outer bracts spreading. 



3. T. Icevigatum (DC). Leaves dull green, pinnatifid, 

 or cut up into linear segments, generally small, or 

 about 3 or 4 inches in length. 



4. T.palustre (DC). Leaves, when in rich soil, entire 

 and deeply- toothed. 



The above are all easily recognised ; nay, speaking 

 with a learned botanist from Narbonne, he pointedly 

 declared his conviction that Nos. 2 and 3 were good 

 species. The flowers differ so little from the normal 

 form that I do not think they are reliable as charac- 

 ters, although Babington seems to depend much 

 upon the outer bracts ; however, flowers can be 

 found where the bracts vary widely on the same plant. 

 The leaves preserve the same peculiar shape under all 

 circumstances ; I can with every confidence rely upon 

 them. T. Icevigatum are very peculiar, being cut to 

 the midrib into long linear leaflets. The opposite 

 extreme is seen in T. pahistre ; here the leaves are in 

 some examples quite entire, whilst the rich emerald- 

 green tint of T. Dens-leonis can seldom be equalled. 

 Taking it all in all, I know no species so full of in- 

 terest. In my British herbarium I have about ten 

 sheets filled with this species. 



J. F. R. 



THE DERBYSHIRE CAVERNS. 



UNDOUBTEDLY many visitors to the British 

 Association meeting at Sheffield will avail 

 themselves of the neighbourhood of the Peak (only 

 some twenty miles away) to explore its wonderfully 

 lovely dales and caverns. We extract the following 

 account of the "Speedwell Cavern," at Castleton, 

 from " Geological Essays, and Sketch of the Geology 

 of Manchester and the Neighbourhood," by J. E. 

 Taylor (published in 1864). 



The entrance to the " Speedwell " mine is by a 

 door in the hillside, strongly reminding one of that 

 which Bunyan mentions in his " Pilgrim's Progress," 

 as shown to Christian by the shepherds. In at this 

 door one starlight night in February, some four or 

 five of us entered, each laden with a wardrobe of 

 miners' clothing wherewith to bedeck ourselves. 

 Entering at the cottage by the side of the cavern, in 

 which the guide usually lives, we found a cheerful fire 

 burning. We speedily converted this into a dressing 

 room, and then turned out in anything but a photo- 

 graphicable condition. I may, observe, however, 

 that the cavern itself, the "Speedwell" mine, does 

 not require this trouble at the hands of ordinary 

 visitors. It is, as the handbills advertise, " quite 

 clean and fit for ladies to visit." There is also an 

 intelligent guide to accompany them, and to point 

 out various objects worthy of remark. Entering in 

 at the door by the hillside, we descended a flight of 

 upwards of a hundred steps, and at the bottom, to 

 our astonishment, found a boat ready to row us along 

 a subterranean passage in which was about three feet 

 of water. There was just sufficient room to sit upright 



