442 SYSTEMATIC BOTANY. 



Sub-order 5. Se^ptulatce. — The valves of the fniit opening 

 longitudinally, and bearing transverse septa in their interior. 

 No examples among British plants. 



Sub-order 6. Lomentace(e. — Fruit a siliqua or silicula, dividing 

 transversely into 1-seeded portions, the true siliqua sometimes 

 barren ; the beak placed above it containing one or two seeds. 

 Examples : — Cakile, Raphanus. 



These sub-orders are further sub-divided into Tribes, according 

 to the mode of folding of the embryo. 



The sub-orders founded on the mode in which the embryo 

 is folded, are as follows: — 



Sub-order 1. Pleurorhizecs (0 = ) {fig- 759). — Cotyledons 

 accumbent, flat; radicle lateral. Examples: — Cheiranthus, 

 Arabis. 



Sub-order 2. NotorhizecB (O II) (,fig- 758). — Cotyledons incum- 

 bent, flat ; radicle dorsal. Examples : — Hesperis, Isatis. 



Sub-order 3. Orthoplocece (O ^) {fig- 870). — Cotyledons con- 

 duplicate, longitudinally folded in the middle ; radicle dorsal, 

 within the fold. Exa7nples : — Brassica, Raphanus. 



Sub-order 4. SpirolobecB (Q \\ ||) (figs. 757 and 869).— Cotyle- 

 dons twice folded, linear, incumbent. Examples: — Bunias, 

 Erucaria. 



Sub-order 5. Biplecolohem {Q \\ \\ ||). — Cotyledons thrice folded, 

 linear, incumbent. Examples: — Senebiera, Subularia. 



Distribution and Numbers. — The plants of this order chiefly 

 inhabit temperate climates. A large number are also found 

 in the frigid zone, and a few in tropical regions chiefly on 

 mountains. According to Lindley the order includes about 1,600 

 species. 



Froperties and Uses. — This order is generally characterised 

 by antiscorbutic and pungent properties, frequently combined 

 with acridity. The order is one of the most natural in the 

 Vegetable Kingdom, and does not contain a single poisonous 

 plant. The seeds frequently contain a fixed oil. Many of our 

 commonest culinary vegetables are derived from it. The Cruci- 

 ferse are also interesting in a chemical point of view, as many 

 of them contain much nitrogen and sulphur, and, according to 

 Mulder, the common Water-cress {Nasturtium officinale) contains 

 iodine. The more interesting plants are the following : — 



Anasfafica hierochuntina, Rose of Jericho.— This plant, which is found wild 

 in the deserts of Egypt and Syria, is remarkable for possessing hygrometric 

 properties. Thns, when it is "full grown, and its branches have become dry 

 and withered, it contracts and coils up, so as to assume the form of a ball, 

 in which state it is blown about by the winds from place to place ; but if it 

 be then exposed to moisture, it uncoils, and the branches expand again, as if 

 again possessed of life. " Some superstitious tales are told of it, among 

 which, it is said to have first bloomed on Christmas Eve to salute the birth 



