166 GUERMNSE Y. 
Mercurialis annua, L. Annual Dog's Mercury. 
Colonist. First record: Gosselin, 1815. 
Very common. One of the most abundant weeds in gardens and 
cultivated fields in every part of the island. 
The patois name of this plant is Fozvolle, the same as in 
Normandy, where the word is sometimes varied to Fotvoude. This 
species offers one of the extremely rare examples of parthenogenesis 
among phanerogams. Carefully conducted experiments have con- 
clusively proved that the unfertilised ovaries do occasionally produce 
fertile seed, though less in quantity than that resulting from pollina- 
tion. See Kerner and Oliver’s Vat. Hist. of Plants, 1895, vol. ii. 
p. 465. This plant has the reputation of being poisonous. 
(Ceratophyllum demersum, L., the Hornwort, is marked for 
Guernsey in the list given in Ansted’s Channel Islands, but there is 
no satisfactory evidence of its occurrence in these islands.) 
CALLITRICHACEAE. 
Callitriche verna, L. Common Water Starwort. 
Native (?). First record: Gosselin, 1815. 
In #7. Sarn. Babington notes this species as common in all the 
islands, and Gosselin gives it in his list as the only species found by 
him. Ten years ago I collected in a pool at Baubigny, and in a 
quarry pool near La Moye, Vale, plants which appeared to me to 
belong to this species; but unfortunately I kept no specimens, so 
that it must remain for the present uncertain whether the true 
Callitriche verna occurs in Guernsey or not. 
Callitriche obtusangula, Le Gall. 
Native. First record: Marquand, 1891. 
Rare, but abundant where it occurs. Ditch on the lane side at 
Grande Mare. Meadow drain at Les Goubais (1x.). Ditches 
between Ivy Castle and Baubigny. Quarry pool at L’Islet. 
Callitriche stagnalis, Scop. Largefruited Water Starwort. 
Native. First record: Marquand, 1891. 
Common in shallow pools and ditches; often growing on the 
mud on wet roadsides. 
Callitriche hamulata, Kutz. Hooked Water Starwort, 
Native. First record: Babington, 1839. 
Rare. Ivy Castle ditches. Quarry pool at L’Islet. A very 
slender and beautiful form occurs in a large and deep quarry pool at 
Mont Cuet, Lancresse. Under the name of C. pedunculata, DC., 
this species is noted in 7. Sarn. from ‘near Paradis, and by the 
roadside near Bordeaux Harbour.’ 
