OF ARTS AND SCIENCES. 83 



and the horned or awned costas of the latter correspond to the mid- 

 nerves of the bracts. 



This bracteate division (the AtripUcece) is connected with the 

 Ghenopodiece by the genera BUtum and 3fonolepis, with their often 

 fleshy sepals reduced in number, and especially by M. chenopodioides, 

 in which the solitary so-called sepal is evidently foliaceous. Some of 

 the species of Atriplex show a still closer connection, as A. hortensis 

 and others of the section Dlchospermum, in which the fruit may upon 

 the same plant be either horizontal and included within a normal calyx, 

 or vertical and compressed between broad foliaceous bracts, but wholly 

 without calyx. Other species have within the bracts, occasionally or 

 constantly, a more or less regular calyx of several well-developed 

 sepals. On the other hand, in A. Omelini fertile flowers are some- 

 times found without either bracts or calyx. 



The position of the seed as vertical or horizontal is mainly deter- 

 mined throughout the order by the nature of the calyx, being horizontal 

 whenever the calyx is regular and appressed to the fruit, and for the 

 most part vertical if it be either absent, or loose and urceolate or tubu- 

 lar, or reduced to fewer than the usual number of sepals. The character 

 of the seed-integument (simple or double), upon which the Eurotiete 

 and Camphoracece are separated from the Ghenopodiece, has less value 

 than Moquin gave to it, as is apparent in the SalicornecB and SumdecB. 

 Among the North American genera, the only one {Kochia) referred by 

 Moquin to the Camphoracece has evidently a double testa. 



A nectary or disk very rarely occurs in either male or female 

 flowers. In Sarcohatus only, which is in several respects a remark- 

 able genus, do they become conspicuous. The pistillate flower has here 

 a calyx and develops a horizontal wing similar to that of Salsola ; 

 but the inner portion of the envelope is in other respects very different 

 and peculiar, and must probably be considered an expansion of a perigy- 

 nous disk enclosing the membranous ovary. The male flower is even 

 more anomalous, having neither calyx nor bracts, but a central peltate 

 scale about which the stamens are arranged, and which appears to be 

 an extraordinary development of a central nectary. 



Synopsis of Grenera. 



Suborder I. SPIROLOBEJ?}. Embryo spiral. Seed-integument double 

 albumen none or scanty. Saline herbs or shrubs, with fleshy Uuear leaves 

 the stems not jointed. 



* Embryo conical-spiral. 



1. Salsola. Elowers perfect, axillary, 2-bracted ; calyx 4-5-parted, trans- 

 versely winged in fruit : seed horizontal, with a membranous testa. 



