SPERMATOPHYTA 401 



the Chenopodiaceae, to which belong the goosefoots (Chenopodium), beet 

 (Beta), spinach (Spinacia), etc.; the Amaranthaceae, including pigweed 

 (Amaranthus) and coxcomb (Celosia); the Portulacaceae, represented by 

 Portulaca; and the Caryophyllaceae, containing the carnation and pinks 

 (Dianthus), catchfly (Silene), chickweed (Stellaria), etc. 



The flowers are mostly perfect, regular, mostly hypogynous, syncar- 

 pous, and usually pentamerous. The perianth may consist of either one 

 or two whorls. The ovary is mostly unilocular. The Centrospermales 

 represent a transition between the apetalous and choripetalous dicotyle- 

 dons, as the lower families have a bract-like undifferentiated perianth, 

 while the higher families have a distinct calyx and corolla, the latter being 

 very showy. A characteristic feature is the presence of abundant peri- 

 sperm in the seed. This takes the place of endosperm as a food-storage 

 region. The Centrospermales show some resemblances to the Poly- 

 gonales, and the two orders may be related. 



Ranales. The Ranales are a great genetic order, comprising 16 families 

 and about 5,000 species of herbs, shrubs, and trees. The largest family, 

 the Ranunculaceae, has 1,200 species, and includes such common forms as 

 buttercup {Ranunculus), Hepatica, Anemone, Clematis, columbine {Aqui- 

 legia), larkspur {Delphinium), and peony {Paeonia). Other important 

 familes are the Nymphaeaceae, Berberidaceae, Magnoliaceae, and 

 Lauraceae. 



This order is ill defined. The flowers are perfect and mostly regular, 

 but some are irregular. The perianth, usually consisting of a distinct 

 calyx and corolla, is often undifferentiated and petaloid. Although the 

 floral parts are often indefinitely numerous and wholly or partly spiral, 

 there is a strong tendency toward the establishment of a cyclic condition 

 with definite numbers, especially in the perianth. Hypogyny and apo- 

 carpy are features of the order, perigyny and syncarpy being infrequent. 

 In the Berberidaceae and Lauraceae the carpels are reduced to one. 

 The Ranales are generally regarded as a primitive order that has given 

 rise both to the more specialized orders of dicotyledons and to the 

 monocotyledons. 



Papaverales. This order represents a specialized offshoot from the 

 Ranales. There are 6 families and about 3,600 species, the principal fam- 

 ilies being the Papaveraceae, Fumariaceae, and Cruciferae. The Crucif- 

 erae, with 3,000 species, includes such well-known forms as the mustards 

 {Brassica), radish {Raphanus), Alyssum, stocks {Matthiola), shepherd's- 

 purse {Capsella), etc. The flowers of the Papaverales are mostly regular, 

 hypogynous or sometimes perigynous, and syncarpous. The flowers are 

 cyclic except that the stamens are spiral in some members. The pistil 

 usually consists of two united carpels, syncarpy being the chief point of 



