390 ON SEEDLINGS 



leaves are abruptly pinnate. The first pair of leaves in this 

 species and in Indigofera australis (fig. 274) being opposite and 

 simple recalls what occurs in the tribe Phaseoleae as described 

 below. The early stage of Galega officinalis recalls that of a 

 Trifolium or Melilotus. This is also the case with Carmichaelia 

 pilosa, but the first four leaves at least are simple, obcordate, 

 and small. The leaves of the adult plant are often exactly 

 similar to the primary ones, but some of them are pinnately 

 trifoliolate or imperfectly so. Broadly oblong-oval cotyledons 

 occur in Kobinia Pseud-Acacia (fig. 275) and in some species 

 at least of Colutea. The first leaf of the former is simple and 

 the second pinnately trifoliolate. Both this species and In- 

 digofera australis as well as Galega officinalis show a gradual 

 evolution of the leaves. 



Large and broadly oblong cotyledons more or less falcate 

 and sinuate on the sides or unequal at the base occur in 

 Psoralea sp., Sesbania tomentosa (fig. 277), S. grandi- 

 flora, Calophaca grandiflora, in a new, unnamed species of 

 Calophaca, Astragalus juvenalis, and A. thianschanicus (fig. 

 278). Those of A. sulcatus are much smaller, and both turned 

 to one side of the stem, as are also those of the unnamed species 

 of Calophaca, and Astragalus juvenalis. This phenomenon, 

 together with the shortness of the petioles and the fleshy 

 character of the lamina generally, indicates a tendency on 

 the part of the cotyledons to become subterranean. The 

 first leaf of Astragalus sulcatus is generally digitately tri- 

 foliolate, while the second bears only the terminal leaflet, 

 but individuals may vary ; and there is a gradual evolu- 

 tion of the leaves from those of the small or weak seedling 

 to the adult plant which has imparipinnate leaves with very 

 numerous leaflets. The other species of Astragalus above- 

 mentioned also show a very gradual evolution of the leaves. 

 The two first leaves of Psoralea sp. are cordate and oppo- 

 site. All the four species of Sesbania above-mentioned 

 show a remarkably abrupt form of evolution. The first leaf 

 of S. grandiflora is lanceolate-oblong, of considerable size, 

 and simple, while the second leaf is abruptly pinnate with 

 four pairs, and the third with five pairs of narrowly oblong 

 leaflets. The first leaf of S. tomentosa is obovate-oblong 



