212 



NATURAL HISTORY OF PLANTS. 



opposite or in whorls of three. They are also opposite in several 

 species oi^EtMonema, Eunomia, Cawjyt/lojjfera, Moriera, &c. In form 

 they may be simple, entire, lobed, dissected, or runcinate. Some 

 have the blade deeply divided down to the midrib, which is not, 

 however, articulate as is usual in compound leaves. Often the 

 cauline leaves are sessile, auriculate or amplexicaul, while those mis- 

 named radical are petiolate and more deeply lobed. 1 



4. Stipules are usually absent in this order, and some have wholly 

 denied their presence. 2 But several authors 3 state that they are quite 

 conspicuous at first in certain species ; though their development 

 soon stops, and they are only represented in the adult stage by little 

 gland-like bodies. 



5. The state of the surface is variable in the leaves, as in many 

 other organs. They are often glabrous ; but when they are more 

 or less downy, it is due to soft or rigid hairs, simple, bi- or tri- 

 furcate, stellate, or medifixed, more rarely capitate and glandular. 



6. The inflorescence is usually indefinite, very frequently racemose. 

 Sometimes it is corymbose ; between these two forms we find every 

 transition ; so that the corymb often becomes a raceme as the fruit 

 ripens, owing to the elongation of its axis. The inflorescences are 

 usually terminal or leaf-opposed, more rarely axillary ; they often 

 become compound when the lateral groups are axillary not to leaves, 

 but to bracts taking their places towards the top of the stem. Ex- 

 ceptionally the flowers are solitary, axillary or terminal. The flower 

 or flowers often terminate what is called a scape, an axis more or less 

 denuded below. 



7. The bracts to which the flowers are axillary are usually absent 

 in Cruciferce. However, genera are cited such as Porjj/tj/rocodo/t, 

 Stenonema, Psychine, Dipterygium, Schizopetalon, Ionopsidium, &c, 

 wherein they exist to some extent ; others whereof some species alone 

 have bracts ; and finally, in some species we find in a single inflo- 

 rescence some flowers ebractate, others with bracts visible at the base> 



1 The leaves of Nasturtium, Cardamine, &c., 

 sometimes bear adventitious buds, more or less 

 developed, usually springing from the ribs. (See 

 Picart-Jourdain, in Soc. Linn, du Nord, i. 

 (1840).— Tukp., in Compt. Rend. Acad. Sc, ix. 

 (1839).— A. S. H., in Ann. Sc. Nat., ser. 3, ix. 

 190 



2 Payee, Organog., 210. 



3 Krause, in Bot. Zeit., iv. (1846), 142.— 

 DrcuAETKE, in Rev. Bat., ii. (1846), 207.— 

 Norman, in Ann. Sc Nat., ser. 4, ix. 105. — 

 Godk., iu Ann. Sc Nat., ser. 5, ii. 281. 





