ON THE JESTIVATION OF CRITHMUM MARITIMUM. 
By BERTHOLD SEEMANN, Pu.D., F.L.S. 
: Mr. J. T. Boswell Syme has drawn my attention to Crithmum mari- 
timum as a second British Umbellifera having a truly valvate estiva- 
tion, and obligingly supplied me with fresh specimens of the plant. 
Mr. Syme is perfectly right in regarding the zestivation of Crithmum 
as valvate, and all those who have looked at the buds under the mi- 
eroscope have satisfied themselves on that point. The petals are in- 
flexed at the apex, as is the case in many allied genera, but their edges 
are truly valvate. It is a matter of importance to ascertain the zesti- 
vation of all the plants regarded by us as Umbelliferze and Araliaceæ, 
because, for systematie purposes, most useful characters are to be found 
init; and as there is a vast number of species to be examined, it is 
desirable there should be a good many observers. I am more and more 
convinced that the only clear line between Umbelliferze and Araliacee, 
or, as T should prefer calling the latter, Hederaceze, can only be drawn 
by relying upon the characters derivable from the zestivation of the co- 
rolla. Not one of the distinctive characters usually assigned to the 
two Orders holds good, and in elementary books this state of things is 
extremely puzzling to the student. If, for instance, a beginner wished 
to find Hydrocotyle and Crithmum by means of the analytical key given 
in one of our leading local Floras, he could never hope to succeed, 
After getting to the neighbourhood of the Orders in which they are 
placed in that work, he. would meet with the following enigma :4— 
* 33. Petals imbricate in 1 Re 
Petals valvate in bud. 
Of course, having ascertained the petals to be pede in bud, he would 
continue his search by turning to ** 35," and there find,— 
* Fruit a berry. Styles several. Leaves alternate. Araliacee.” 
Now as neither Hydrocotyle nor Crithmum have a berried fruit and 
more than two styles, his search for the two genera by means of this 
analytical key would have come to an end. I have quoted this exam- 
ple, out of many, because it came ready to hand, and it illustrates the 
practical inconvenience arising from our neglecting the estivation. The 
conspectus of the calycifloral Orders given in Hooker and Arnott’s 
* British Flora,’ places the student in the same dilemma, 
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