154 THE JOURNAL OF BOTANY 



A KEY TO BRITISH HEPATITE. 

 By Symers M. Macvicar. 



The following key being intended for the less advanced student 

 and for beu^inners, 1 have used easily-observed characters as far as 

 possible, and have only made use of those derived from tlie in- 

 florescence or perianth where these are necessary, or are generally 

 present. This unavoidably lessens the exactness of the key, but it 

 seemed better not to depend mainly on characters which are either 

 rarely to be found in the British species, or are too difHcult for 

 beginners. 



Where there is only one species in a genus, I have not given the 

 character of the genus, but the characters which disiingaished the 

 species. Tlie inflorescence should be known in every case, but, as 

 tliis is the stumbling-block of beginners, a few hints on the subject 

 may be given. In the first place, it is absohitely necessary that the 

 student be sure that he has an entire plant before him. Let him 

 take a tuft of the plant to be examined, place it in a saucer with 

 water, gently knead it with the fingers to remove the soil, and 

 partially to separate the stems ; then place it in another saucer with 

 water, and disentangle an entire plant with needles. This is the 

 most difficult part with the inflorescence of small species as Ccpha- 

 luzia, the stems being very delicate and closely interwoven. In 

 such cases it is sometimes advisable to use camel-hair brashes 

 instead of needles. With paroicous species the antheridia will 

 seldom be found beneatli old perianths : it is better to examine 

 plants with perianths which are immature. If it is a paroicous 

 species which innovates beneath the mature perianth, swollen 

 bracts with antheridia may be seen towards the apex of the 

 branches, and young female flowers be detected by turning down 

 the uppermost leaves. The male bracts of a large number of 

 species resemble the ordinary leaves, except that they are more 

 swollen at base, and are imbricated. They may form a terminal 

 spike, or give an interrupted appearance to the middle of the stem. 

 Some genera have their inflorescence on short lateral or postical 

 branches, the male bracts often forming a small catkin, and 

 dift'ering from the leaves. They are usually readily detected, but 

 the student must not expect to find the inflorescence in every 

 plant. Much care and patience are required, but with a little 

 practice it becomes not difficult to detect male bracts, and young 

 or sterile female flowers. In the swollen male bracts there is very 

 frequently to be seen an air-bubble, which must not be mistaken 

 for an antheridium. With minute species the finding of the 

 inflorescence is a matter of manipulation which must be over- 

 come. In dissecting off leaves of Acolea (Cesia) species for exami- 

 nation, the student must be sure that they are not female bracts 

 which lie has taken, as these difler in shape fr m the leaves. 



The genera are those used by Mr. Pearson in his Hepatica; of 

 the British Isles, as far as has yet been published. The remainder 

 are familiar, with the exception of rah/cuian'a. where I have followed 



