214 FLOWERS OF GARDEN AND GREENHOUSE 
C. RHOMBOIDEA (rhomboid) is a less interesting form with smaller 
purple flowers, the petals of a rhomboid shape. 
The Clarkias are easily raised from seeds sown annually 
in the open border, either between March and May or in 
the autumn. They are not particular as to the character of the soil, but 
if this is rich the flowering will be profuse. They do not transplant 
well; they should therefore be sown thinly where they are to bloom, 
and be thinned out to a distance of ten or twelve inches. Autumn-sown 
plants begin to flower much earlier than those that were sown in spring. 
Description of Upper portion of Clarkia pulchella with buds, flowers, 
_ Flate103. and capsules. The additional figures are—Il, a flower 
enlarged ; 2, a stamen enlarged; 3, a cross section of the ovary showing 
its four-celled structure; 4, the seed, natural size and enlarged; 5, a 
seedling. 
Cultivation. 
EVENING PRIMROSES AND GODETIAS 
Natural Order ONAGRARIE. Genus Gnothera 
CENOTHERA (Greek, oinos, wine, and thera, hunting ; classical name given 
to some plants whose roots were eaten to provoke the appetite for drink). 
A genus with about a hundred species, with rare exception, herbs. The 
leaves are alternate. Flowers solitary, or in leafy spikes or racemes, 
borne in the axils; large, honey-yielding, white, yellow, red, or purple. 
Calyx-tube four-angled, four-lobed. Petals four, stamens eight, ovary 
four-celled, style threadlike, stigma round or four-lobed. With one 
exception all the known species are natives of America, and but for @ 
few Tropical species these are confined to the Temperate regions. The 
extra-American species is a native of Tasmania. 
Enothera biennis, the Common Evening Primrose, 
and the best known of all the species, was introduced from 
North America in the year 1629. It has taken so kindly to British soil 
that in many places it is thoroughly naturalised and grows wild, whilst 
it has become one of the commonest of plants in cottage-gardens. &. 
mollissima was the next arrival, from Argentina, in 1732, followed by 
. fruticosa, from the United States, five years later. @. parviflora 
and G. pumila both came from North America in 1757 ; the large-flowered 
. grandiflora was introduced from North America in 1778; and é. 
odorata from Patagonia in 1790. The latter, which is well known 1) 
gardens, has become naturalised on the coasts of Somerset and Cornwall. 
