438 



FOURTH GROUP. — SEED-PLANTS. 



connected by short straight anastomoses into a lattice-like network, as in Alistna 

 Cos/iis and Ouviraiidra, in the last of which the mesophyll which is present in the 

 meshes of the young leaves is wanting in the older ^ In a few cases only projecting 

 lateral veins proceed from the mid-rib and give rise to a delicate reticulated venation, 

 as in some Aroideae. 



Fig. 367. Floral di; 

 of Museae. 



36S, Floral diagram of Zingibereae. A Nt\/v 

 chiutn. after Le Maout and Decaisne. B Alfhiin, 

 after Payer. 



FIG. 369. FInral diagram 

 of Canneae, after Payer. 



FIG. 371. Floral diagram 

 of TriglochiH (Juncagi- 

 neae). 



Fig. 372. Floral diagram 

 of Gymnestachys (Aroi- 

 deae), after Payer. 



The flower of the Monocotyledons usually consists of five alternating isomerous 

 whorls, an outer and an inner perianth-whorl, an outer and an inner stamina! whorl, 

 and a carpellary whorl followed by a second only in the polycarpous flowers of the 

 Alismaceae and Juncagineae. The most common typical floral formula is therefore 

 Sn Pn Shi + n Cn (-!-'/)• The number of the staminal whorls is increased in the 

 Hydrocharideae only and in a few other cases ; where, as in Butot7ius, there is an 

 increase in the typical number of the stamens, this takes place without multiplication 

 of the whorls. The number of the members in a whorl is two only in some isolated 

 cases scattered through very diff'erent families, as -S 2 P2 6"/ 2 -f- 2C 2 in Maianllmmim 

 and some Enantioblastae ; it is sometimes four or even five in Paris qiiadrifoUa and 

 some Orontiaceae. The usual number of parts in a whorl is three and consequently 

 the typical formula is ■S'3 i^s 6V3 + 3 C 3 (-f-3)- 



Observed in specimens in the Botanic Gardens at Stiassburg. 



