
NATURAL ORDERS 97 
| (Fig. 66, a), for usually the leaves of a flower are situated in 
the receptacle one immediately above the other, so that | 
practically there are no internodes. In this species of Lychnis 
as well as in Lychnis vespertina (White Campion), the staminate 
flowers are on one plant, the pistillate on another. The stamens 
are in 2 whorls, both of which are always developed in this 
group, whilst in the Stellaria group the inner whorl of 
stamens is often wanting. The carpels are 5, styles 5, 
placentation free central. The fruit is a capsule, dehiscing by 
10 teeth. 
DIFFERENCES IN THE GROUPS. 
ALSINEZE (STELLARIA). SILENEA (LYCHNIS). 
1. Sepals free. Sepals joined, therefore calyx 
tubular. 
2. Inner whorl of stamens may Both whorls of stamens in- 
_ bewanting. © variably present. 
3. The gynecium consists of | The number of carpels varies ; 
3 carpels, and therefore it is often 5, and the fruit 
the fruit dehisces by 6 shows 10 teeth. 
teeth. 
The genera belonging to the Alsinew are often small, creep- 
ing plants growing in dry, dusty places by the roadsides ; 
they have small flowers with white petals, as in the Chick- 
weeds (Stellaria) and Sandworts (Arenaria). Sea-Purslane 
(Arenaria peploides) is abundant on shifting sands and sandhills; 
it has thick, fleshy leaves, with short internodes and a com- 
paratively large fruit. It is one of those sand plants which 
_ ¢an stand being covered up by the fine sand blown on it by 
high winds and yet thrive. The rhizome, as in the case of 
sand-binders, is long and creeping. 
Amongst the Silenew there is often a reduction of carpels ; 
the Campions (Lychnis) have 5, the Nottingham Catchfly 
only 3, the Soapwort and the garden Carnation only 2. The 
number is easily ascertained by counting the styles. 
The genus Polycarpon, by some botanists considered a 
distinct group, differs in some respects from both the Silene 
and the Alsinez. The lower leaves are in whorls of 4, not 2 ; 
the stamens are 3 to 5; the capsule is 3-valved, and the fruit 
