104 



NATURAL HISTORY OF PLANTS. 



with ninniiiL,' rhizomes, from which short branches rise to the 



surface, bearing a rosette of leaves and 

 axillary peduncles, which bear a single 

 flower, or several grouped into a simple 

 or compound raceme. The calyx con- 

 sists of five equal or unequal sepals of 

 imbricated, usually quincuncial aestiva- 

 tion. The stamens are indefinite, hy- 

 pogynous, and become smaller as they 

 are more external. The filaments are 

 free, sometimes collected in three or 

 four distinct groups ; they are dilated 

 above into an elongated flattened con- 

 nective bearing an anther with two 

 linear cells dehiscing laterally or nearly 

 so ;' or else the filament swells into a 

 short head, which, as in Acrotrema, bears 

 the oblique distinctly introrse anther- 

 cells" diverging below ; or, again, each 

 of the elongated anther-cells opens 

 by a round pore near its tip/ The carpels are two in number, free, 

 or slightly coherent towards the base. The ovary contains on its 

 inner angle a placenta which bears either ascending ovules, or two 

 vertical rows of nearly horizontal ovules. The style, often elongated 

 and bent on itself in the bud, ends in a more or less swollen stigma- 

 tiferous head. The fruit consists of two or three capsules dehiscing 

 irregularly to free the curved seeds, which possess a membranous 



iv. 36.— Hook. & 



-Thwaites, Eiium. 



Lid. Bat., i., pars 



Walp., Rep., i. 65 ; Ann. 

 TnoM3., Fl. hul., i. 61.- 

 Pl. Zeyl., 2.— MlQ., Fl. 

 alt., 10. 



* This is especially seen in A. lyralum Hook. 

 F. (Thwait., op. cit., 3), in which the filament, 

 not swollen at the summit, is directly continuous 

 with the connective, and bears two adnate narrow 

 cells of lateral or slightly extrorse dehiscence. 

 The outer stamens are shorter than the others, 

 but all are fertile. The carpels, often three in 

 number, contain numerous ovules, and possess a 

 style dilated at the tip. 



' As in A. Thwnitenii HooK. F. (,4. pbinati- 

 Jidnm Tiiw.), the top of the filament swells into 

 a connective bearing two oblique ellipsoidal cells 



diverging at the base and dehiscing marginally 

 or nearly so. In form these anthers (see fig. 151) 

 recall those of most Tetraceras. There are usually 

 three carpels, with half a score of ovules in the 

 ovary, and a subulate style not dilated at the 

 tip. 



^ This occurs in the typical species A. costa- 

 tum Jack. The stamens, somewhat unequal, 

 bear an elongated anther which at first appears 

 introrse, but the cells of which only open at the 

 tip by pores with thickened edges (fig. 152) — a 

 character of little value (see p. 1 14). The sepals 

 are lanceolate, covered with stiflSsh hairs. The 

 carpels are often two in number ; the style is not 

 dilated at the tip. The ovary contains two 

 ascending ovules. 



