78 CHARACTERS OF CRUCIFER&. 
Exemplaria manca. Caulis herbaceus, teres, adscendens? v. 
erectus, pilis minutis stellatis sparsim coopertus. Folia pe- — 
tiolata, basi cuneato-angustata, ovata v. oblonga, obtusa, mar- 
gine subintegerrimo v. repando-dentato, dentibus obtusissi- - 
mis obsoletis utroque latere duobus v. tribus. Racemi - 
terminales, densi, ebracteati, simplices, multiflori. Pedicelli 
patentes, ealyce breviores, basi glandulis duabus instructi. 
Flores parvi, ut videturaurei. Calyx dense stellato-tomentosus, 
subcanescens, cylindricus, clausus, e foliolis quatuor lineari- 
bus obtusis subaequalibus conflatus, Petala 4, lineari-spa- - 
thulata, obtusa, medio vix angustata, ungue cum lamina con- | 
fluente, basi ampliata, subcordata, membranacea. Stamin& 
6, tetradynama ; filamenta tenuissima, ovario multuplo lon- 
giora. Stylus brevissimus, stigmate magno bilobo terminatus. | 
Silicula biscutata, basi et apice emarginata, sessilis margine 
incrassato, densé ciliato, disco compressissimo parcé hispido: 
Semen in utroque loculo unicum, compressum, immarginatum, 
horizontale. Radicula descendens! septi basin spectans, 
accumbens. 
This genus scarcely differs from Biscutella, with which 
it might perhaps, without much violence, be united. Itis 
distinguished by the erect sepals, forming a close calyx, the 
absence of claws to the petals (which in Biscutella are often 
very short) and the minute style. These, I confess, are buf 
trivial characters. From Cremolobus, to which genus We 
might expect a Californian plant would have more affinity; 
it differs by the far more important character of the direction. 
of the radicle, and by the sessile silicule. On the whole, l 
have thought it best, taking into consideration the geogr 
phical position of Biscutella, to assign to the North America" 
plant a distinct place in the system, though possibly a pro 
visional one. The generic name is compounded of às 
Ovpeos, and is therefore nearly synonymous with Biscutella. 
Tas. V. Dithyrea Californica, with flowers and fru 
Fig. 1. Flower. f.2.Petal f. 3. Stamens and pistil. F 
Fruit. f. 5. Seed. f. 6, Embryo.—magnified. — E 
Dec. 13, 1814. 
