56 
RXHiniTTON MRETINC, 1952 
Species or IIELIANTHEMUM with Special Reference to H. CANUM 
A map showed the distribution of the four species of Helianthemum 
in Britain. The actual localities of II. guttatum (L.) Mill., II. apen- 
ninvni (L.) Mill. (II. poUifuUuni (Huds.) Mill.) and Bl. mnuni (L.) 
Baumg. were sliowu by different-coloured crosses, while for II. cliamae,- 
cistus Mill, the vice-counties in which this species is found were shaded 
in pencil, thus showing its abundance in comparison with the rareness 
of the other three species. The different localities of the three former 
species were also listed on a separate sheet, while II. chamaecistus was 
mentioned only as being the most widely distributed species, occurring 
on the chalk downs and carboniferous limestone outcrops in various 
parts of Britain, the sites being too numerous to list for the exhibit. 
An accompanying table showed the difference in the habit, leaf, 
stipule, pedicel, sepal, petal, and style of the four species. 
Herbarium sheets of II. eariuvi were shown, and material from the 
Gower Peninsula illustrated the great range of variation in leaf shape 
n. GUTTATUM 
TI. APENNINiuM 
(77. POLUFOLIUM) 
77. GHAMAEGTSTUS 
77. GANUM 
HABIT 
1.EAF STIPULE 
Erect annual. 
Basal leaves 
forming s rosette. 
Stem with long 
white hairs. 
Nearly sessile, 
lanceolate, hairy. 
Tiinear-oblong, 
hairy. Absent 
from lower leav 
Diffuse much- 
branched under- 
shrub with a 
central rootstock 
from which the 
branches arise. 
Stem densely 
tomentose (grey- 
white felt). 
Petiolate, lanceo- 
late, white-tomen- 
tose below, less so 
above. Margin 
strongly revolute. 
Ta near-oblong, 
narrower than 
a. guttatum. 
Hoary. 
Ditto. Stem 
brown, slightly 
pubescent, upper 
parts of flowering 
axes hoary, the 
pedicels more so. 
. 
Petiolate, lanceo- 
late to ovate, 
white-tomentose 
below, nearly 
glabrous above, 
hairy along the 
margin. 
Linear-oblong, 
pubescent. 
Smaller and more 
(compact under- 
shrub (cushion 
habit). Stem 
brown below, 
hoary above. 
Petiolate, to 
nearly sessile, 
leaf shape very 
variable; usually 
lanceolate to 
ovate. 
Absent. 
(77. BEEWETU) 
Stunted form of H. guttatum, leaves rather 
more obtuse and broader and usually bracteate 
pedicels (U. guttatum. usually ebracteate). 
