PLATE XV.— CHICKWEED (Stellaria media), MAIDEN PINK (Dianthus deltoides), and CAMPION (Lychnis vespertina). 



duckweed. 



The common name of Chickweed is applied to two different genera of the same order — the one being Stellaria, which is easily known 

 by the line of hairs on stem and branches, and the other Cerastium, distinguished as Mouse-ear Chickweed. Stellaria has been chosen 

 for representation, which is common on roadsides and waste places at almost any season of the year, and though small it forms a very 

 good example of a large and varied class of plants. The flowers are not very 'conspicuous, the petals being overtopped by the sepals, 

 and the pollen is ripe before the stigmas are ready to receive it. The inner stamens are often absent, and even the outer are sometimes 

 reduced to three. 



Stem and Leaves — 



Fig. 1. Stem, swollen at the nodes, with a line of hairs on alternate sides. 



Leaves, opposite, and successive pairs forming right angles with each other. 

 Branches, formed in the axil of each leaf, hence two spring from a node. 

 Flowers — 



Figs. 1 and 2. Inflorescence — the main axis terminates in a flower, and two lateral axes below that are similarly terminated 

 by a flower, and so on. Generally when an axis produces a flower at its apex its growth is closed; hence such an 

 Inflorescence is called Definite. 



When a definite inflorescence produces two lateral axes of equal value in this way, it is called a Cyme of two 

 branches, or a Dichotomous Cyme. 



Fig. 3. Sepals, longer than petals. 

 Petals, bifid. 



Stamens, with slender filament arising from receptacle beneath ovary. 

 Carpels, united; Styles, free. 



Diagram. — Calyx, of five free sepals. 

 Corolla, of five free petals. 



Andrcecium, of five long stamens alternating with petals, and five short alternating with five lone;. 

 Gynoecium, of three united carpels. 



Foliage- and Floral-Leaves — 



Fig. 4. Lower Foliage-leaves with stalk ; upper, sessile. 



Fig. 5. (a) Free Sepal, with broad base of attachment. 

 (l>) Petal, deeply cleft 



Fig. 6. Stamen, with glandular swelling at base of filament 



Fig. 7. Gyncecium, with globular Ovary, and three distinct Styles. ^ 



Fig. 8. Placentation, free-central, because ovules are attached to a central axis free from wall of ovary 



Fruit and Seed — 



Fig. 9. Fruit, a dry, dehiscent Capsule, opening by six valves, and containing numerous seeds. 



Figs. 10 and 11. Seed, with curved Embryo enveloping Endosperm. 



Maiden Pink. 



Figs. 12 and 13. Pink, in its first condition, with stamens mature and projecting ; second condition, with stigmas mature, and 

 occupying position of the shrivelled-up stamens. 



Campion. 



Campion, like the generality of flowers which expand by night, is white; since white is a colour which reflects even the faint light 

 existing at night-time, thus rendering objects of that colour as conspicuous as possible. It also smells in the evening in order to guide 

 and attract insects. 



In Chickweed, the male and female organs exist, but there is a tendency to reduction in the stamens, and the pollen is shed before 

 the stigmas of the flower are mature. In Pink, male and female organs also exist, but the pollen is shed while the stigmas are not 

 only immature but concealed. In Campion, the separation of the male and female organs has gone further, since the male and female 

 flowers are produced on separate plants. 



FigS. 14 and 15. Male Flower, with ten Stamens — five long, alternating with sepals, and five short, alternating with petals. 



Corona, at junction of claw and blade of petal, scale-like — essentially a ligular appendage, occupying same position and 



at right angles to leaf as in Grasses. 

 Axis of flower, developed between sepals and petals. 



Fig. 16. Female Flower, with five curling stigmas, thus offering a large surface for the reception of pollen. 



CLASSIFICATION 

 Class. — Dicotyledon. 

 Division. — Polypetalse. 

 Sub-division. — Thalam i fl orae. 

 Order. — Caryophyllaceae, or Pinks. 



Stem, with swollen nodes. 



Leaves, opposite and entire. 



Inflorescence, definite. 



Flowers, regular. 



Stamens, definite. 



Ovules, many, and Placentation free-central. 



Fruit, a capsule (usually). 



Seed, with endosperm. 

 Genera. — Stellaria, Cerastium, Dianthus, Lychnis. 



