MELANDRYUM 
7i 
usually greyish with dense short glandular hairs. Inflorescence dichasial, one of the lateral branches 
shorter than the other or even abortive. Flowers dioecious, very rarely monoclinous, somewhat 
nodding, faintly scented, opening in the evening and remaining open until the middle of the 
following day (or even rather longer in dull weather or in shady situations) ; late May to autumn. 
Calyx with glandular hairs, often tinged with anthocyanin, sometimes greenish, with lanceolate teeth ; 
of the staminate flowers cylindrical, constricted above, with 10 veins ; of the pistillate flowers tapering 
conically upwards from a dilated base, with up to 20 conspicuous and anastomosing veins, somewhat 
thicker than in the staminate flowers, distended or even broken in fruit. Petals white, rarely rose- 
coloured, larger in the pistillate than in the staminate flowers ; limb bifid half-way down, sometimes 
with lateral lobelets ; coronal ligules 2, long, fringed ; claw long, exserted, auricled. Stamens within 
the tube, filaments hairy at the base, represented by staminodes in the pistillate flowers. Ovary 
green, in the staminate flowers represented by a slender thread which occasionally bears a stigma. 
Capsule broadly oval-conical, opening at the apex by 10 teeth which spread slightly outwards but 
which do not roll back, wall thicker and aperture narrower than in M. dioicum. Seeds 00 , grey, 
black when wet, bluntly tuberculate, i - 5 mm. long. 
The flowers are pollinated by night-flying moths. 
For detailed observations on the flowers see Magnin (in Ann. Soc. Bot. Lyon. 203 (1889); ibid. 1 (1891)) and Goebel 
{Biol. Centralbl. 697 (1910)). 
Plants with rose-coloured petals but with all other characters of the species are sometimes met with (=var. coloratum 
Rostrup in Vidensk. Meddel. Nat. For. Kjobenhavn , pp. 82 et 117 (1864)): suspicion attaches to these being of 
hybrid origin. 
(/3) subvar. laciniatum Compton in Camb. Brit. FI. iii, p. 71 ; M. vespertinum var. laciniatum Lange 
Dansk. Ft. ed. 3, 343 (1864). 
Petals doubly bifid. 
This subvariety occurs chiefly in pistillate flowers : the character fluctuates greatly on the same individual. 
A weed of arable land, and in hedgerows ; favouring a dry atmosphere and a rather light 
soil ; demanding good illumination ; almost throughout the British Isles, northwards to Orkney ; 
ascending to about 300 m. 
Europe (except Arctic, and ascending to 1715 m. in Switzerland); northern Africa; Asia; 
North America (not indigenous). 
M. album x dioicum Compton in Moss Cambr. Brit. FI. iii, 71 ; cf. Lychnis dio'ica x diurna Reichenbach 
FI. Germ. Excurs. 825 (1832); M. pratensev. sylvestre Lamotte Ft. Plat. Centr. Fr. [ex Mem. Acad. Clermont ] i, 131 
(1877); Lychnis alba x dio'ica Druce Ft. Berksh. 88 (1897); M. album x rub rum Giirke Plant. Eur. ii, 327 (1903). 
The first generation hybrids (Fj) between M. album and M. dioicum have been produced artificially by various workers ; 
and plants essentially similar to these are frequently found growing wild with the parents. The reciprocal crosses produce F t 
hybrids which differ from one another in some slight particulars; but both crosses are matroclinous. The fullest account of 
these is that by Gagnepain {Bull. Soc. Bot. France xliii, 129 (1896); ibid, xliv, 441 (1897)). Segregation occurs in subsequent 
generations ; and a whole series of intermediate forms occur. These however have as yet only been imperfectly studied. 
Some of the intermediate forms have been given names as follow : — L. dioica var. intermedia Gardiner FI. Forfarshire 28 
(1848); M. dubium Hampe ex Garcke FI. Nord- und M.-Deutschl. ed. 6, 66 (1863); M. intermedium Schur PI. Transsilv. 
106 (1866); M. hybridum Briigger in Jahresber. Naturf. Ges. Graubiind. xxix, 55 (1886). 
The descriptions of the above forms differ to some extent from one another; and the particular forms which have been 
described are no more worthy of being specially named than many others of hybrid origin. Moreover, the descriptions are 
not precise enough to enable one to associate them respectively with any hybrid-forms which have been produced experimentally. 
(A) The Fj hybrid. 
Perennial. Shoot as strong as in M. album. Petiole more winged than in M. album. Laminae 
broader, not so thick as in M. album , less hairy and therefore greener, less undulate. Flowers 
appearing rather later than in M. dioicum , earlier than in M. album. Calyx closely resembling 
that of M. album. Petals with somewhat exserted claws, expanding in the morning and remaining 
open all day even in bright sunlight, colour varying from pale rose early in the season to much 
darker rose in late summer. Pollen containing a considerable proportion of bad grains. Ovules 00 , 
good. Capsule more woody than in M. dioicum , aperture narrower, teeth bent widely outwards 
but not rolled backwards when dry. Seeds tawny in M. album $ x dioicum $, greyish-violet in 
M. album $ x dioicum $. 
(B) The F 2 generation contains about 25 per cent, of white-flowered plants (these subsequently breeding true to 
whiteness) and 75 per cent, of plants with flowers of varying degrees of anthocyanic pigmentation whose genetical nature 
has not yet been fully investigated. 
The production of colour seems to depend on the presence of two Mendelian factors. Some white-flowered plants may 
lack one of these, some the other; and crosses between representatives of these two classes yield offspring with coloured petals. 
