540 



remarkable, being more or less deeply three-cleft, and 

 each of its branches divided. The calyx, as well as co- 

 rolla, have always something unusual in their conforma- 

 tion, or in their nectary ; and many of the genera are mo- 

 noecious or dioecious." 



" Euphorbia, as a familiar and most distinct genus, 

 may serve as a principal example. It is certainly no less 

 singular than extensive. The calyx of one inflated leaf 

 has four or five marginal teeth, and terminates in as many 

 abrupt coloured glands. The latter are remarkably situ- 

 ated on the teeth themselves; but these teeth seem, to- 

 gether with their glands, to be rudiments of petals. In 

 Euphorbia corollata the glands are actual petals, as thin, 

 expanded, and delicate, as those of Flax ; but scarcely 

 another instance is known, of petals originating in teeth 

 of a calyx." 



" Plukenetia, a very rare plant, has a four-cleft flower, 

 and four-celled fruit, with a climbing stem." 



There are numerous genera besides. Rumphia and 

 Treivia are added to the list in the Linnaean manuscript. 



Order 39. Siliquos.^. " All botanists have acknow- 

 ledged the common affinity of the genera constituting 

 this order, and have denominated them Siliquosa and Si- 

 licatoses. Tournefort called them cruciform flowers ; 

 Linnseus, Tetr adynamia. These plants have mostly in- 

 versely-heartshaped cotyledons, except some Cresses, in 

 which those organs are three-cleft ; the rest agree with 

 the genus Convolvulus ; so this character is no proof of 

 affinity." 



" The stems are herbaceous, except some species of 

 Alyssum, and one Vella. There is no real tree among the 

 whole. The roots are all fibrous, none bulbous or tu- 

 berous," (except perhaps Derttaria.) " Leaves univer- 

 sally alternate, without stipulas, tendrils, prickles, or ve- 

 nomous stings. Inflorescence usually a corymbus, which 

 gradually elongates itself into ixracemus, so that the flowers 

 are corymbose, and fruit racemose. Calyx always of four 



