a new Species of Convolvulus. 155 



The flowers at once proclaimed the plant to be a true Convol- 

 vulus, alien otherwise in aspect as it is entirely from the majority 

 of species of the genus. It belongs, however, to a remarkable 

 group of species similar in habit and locality (C spinosus, Desh., 

 hystrix, Vahl, Forskahlii, Del., sericeus, Burm. &c), found only 

 in the desert plains or wastes of Syria, Persia, and Arabia. It 

 is therefore a matter of considerable interest to find a represen- 

 tative of so peculiar a group in the Canaries, where it is, how- 

 ever, in some degree linked on to the more ordinary twining 

 shrubby forms by the intervention of the scarcely less anomalous 

 C. scoparius, L. fil. 



I could not discover in the plant itself, either on the spot or 

 subsequently, any confirmation of the notion of its being avail- 

 able as a perfume. Both root and wood, leaves and flowers, 

 were equally devoid of fragrance fresh or dry ; nor was there 

 any trace of resin, or essential oil, or glandular exudation per- 

 ceptible in any part of the plant. 



My attention was directed, however, by my guides to its pro- 

 perty of catching fire instantly, and burning readily, whilst 

 green, or even growing, — which would seem to indicate the 

 existence of some inflammable essential oil or principle. This 

 property I verified upon the spot ; and it seemed to be the only 

 character which gave it any value in the estimation of the few 

 country people in the neighbourhood who were at all acquainted 

 with the plant. 



Convolvulus caput- Medusa. 

 C. dumosus humilis nanus pulvinato-caespitosus ramosissimus duris- 

 simus spinosus cinereus ; ramulis abbreviatis lignosis densissime 

 glomerato-intertextis, novellis strictis rigidis acutis spinescenti- 

 bus ; foliis parvis lineari-oblongis v. anguste spathulatis obtusis 

 crassiusculis sericeo-cinereis; floribus axillaribus solitariis breviter 

 pedicellatis parvis extus sericeis, antheris (purpureo-lilacinis) in 

 fauce apparentibus subexsertis ; stylis 2 distinctis filiformibus 

 antheras paulo excedentibus. 



Hah. in sterilibus arenosis saxosisque aridis apricis regionis 

 submaritimae orae occidentalis Insulse Fuerteventurse, Promonto- 

 rium Jandise versus, ad alt. 200-500 fere ped. — Florentem die 6 to 

 Aprilis 1859 inveni. 



A most remarkable and (for its genus) paradoxical species, so 

 excessively dwarfed down and stunted that it has more the ap- 

 pearance, when growing, of a rounded convex stone, covered 

 with a grey Lichen, or of some Madreporiform mass, such as 

 the Brain-coral (Meandrina, Lamk.), than of a phsenogamous 

 plant ; though, when torn up by the root, it presents rather the 

 form and aspect of some enormous grey fungus (Boletus), being 

 a stipitate, pulvinate, often hemispherical or turbinate, hard, 

 woody, spinous mass of densely interwoven, rigid branches, 



11* 



