22 GoRHAM, on the UmbeUiferce. 



natural order Umbelliferse, and doubtless several more not 

 yet examined, have their leaves bordered or fringed with a 

 thickish vein. 



But of all the varieties in venation those which are seen 

 in the two Eryngia {Eryngium maritimum, sea holly, and E. 

 campestre, field eryngo) are perhaps the most singular and 

 illustrative of the vein in question. 



In Eryngium maritimum the leaf, says Sir Wm. Hooker, 

 is " beautifully veiny." This is true ; but the same remark 

 will apply to more than half the leaves of this order, if the 

 eye is assisted by the use of a lens of moderate power in their 

 examination. Nevertheless, there are peculiarities in the 

 veining of this leaf which are not to be found in any other 

 plant, excepting Eryngium campestre, amongst all the Um- 

 belliferge. Its veins are prodigiously large, and, when the 

 leaf is well dried, look more like mas-sive skeletons of ivory 

 or carved woodwork than delicate veins of leaves. Almost 

 all the veins, too, are visible to the naked eye, especially 

 those at the margin, which are exceedingly thick, well 

 defined, and are essentially typical of what I have ventured 

 to call a marginal venation. Besides which, every vein is 

 seen to be much bigger at its termination than at its origin, 

 and every primary vein enlarges as it proceeds towards the 

 circumference, until it terminates in a bulge, which finally 

 tajDers off abruptly into a spine. In fact, the leaf joresents us 

 with the curious anomaly of having almost every costa, vein, 

 and veinlet, larger at its termination than at its commence- 

 ment. Hence the central costa is actually narrower than 

 the vein by which the circumference of the leaf is bomided. 



From the whiteness of the veins the leaf is seen to best 

 advantage on a black ground — a piece of black paper, for in- 

 stance, held under the glasses in which the leaf is mounted ; 

 and as the magnitude of the vein at the margin, conjoined 

 with the fact of its anastomosis with so many other veins, 

 precludes the possibility of its being mistaken for a mere 

 thickened margin, and as the costae themselves, as they 

 ramify Avithin the leaf, are radiating, I propose to class such 

 a distribution by itself, under the name of Radio-margi- 

 natum. 



The Eryngium campestre (field eryngo), which is becom- 

 ing extinct, is similar to the sea holly in the magnitude and 

 Avhiteness of its veins, but dissimilar in their distribution. 

 The field eryngo is feather-veined (pennivenium). I would, 

 therefore, classify it under the name of Marginato-pennive- 

 nium. 



Again, the leaf of Bupleurum rotundifolium (common 



