18 , [Feb. 



the teeth subulate, unequal: perianth torn at the sides into long capillary 

 fringe. 



Hae. With the above. (Nuttall.) 



PTEROSTEGIA. 



P. '^dlphyUu. O- Pubescent ; leaflets binate, each division obcordate or bilobed ; 

 comnnon petiole on the lower leaves very long; achenium with the angles acute. 

 ^. *biloba. Leaves nearly all 2-lobed, the lobes sometimes emarginated. 

 Hab. Near Santa Barbara. Flowering in May. 



P. *micruplnjUa. Q. Somewhat hirsute; leaflets binate, the lower ones 

 twice compounded, divisions obcordate or unequally bilobed, the lobes some- 

 times with a single tooth; common petiole on the lower leaves elongated, the 

 upper leaves sessile ; achenium with obtuse angles. 



Hab. With the above, which it greatly resembles, but always smaller leaved 

 and more pubescent. 



* NEMACAULTS.f 



Involucr urn, none; the flowers monoicous, disposed in round clusters at the 

 joints of the filiform stem, subtended and mixed with elliptical bractes. Feriantli 

 obconic, 6-cleft. Stamens 3. Styles 3, very short, with small subcapitate 

 stigmas. Achenium ovoid, angular only at the summit. — Califirnian annuals, the 

 leaves wholly, and the bractes on the upper side densely and whitely tomentose ; 

 stems smooth or viscid, filiformly elongated and nearly naked, with the flowers 

 disposed in sessile round heads at the joints of the stem, and subtended and 

 mixed with small, elliptical, marginated bractes. The flowers resemble 

 those of Eriogoiium, but the habit, absence of involucrum, and paucity of sta- 

 mens, at once distinguish it. 



N. *denudnia. 



Hab. St. Diego, Upper Californiaj in sandy places near to the sea shore. 

 Flowering in April and May. (Nuttall.) 



N. *foliosa. With the above, from which it perhaps is not distinct; the leaves 

 are much longer, the stem a little glutinous, and with most of the joints of the 

 stem leafy. 



•OXYTHECA.J 



Dioicous or monoicous. Involucrum small, 4 to 5-toothed, obconic, few- 

 flowered, (3 to 5,) the teeth mostly spinulose. Female perianth closed to the 

 summit, about 6-toothed ; male and hermaphrodite shortly 6-cleft. Staments 

 about 6 ? Achenium compressed, Ssided, elliptic. Style 3. Embryo excen- 

 tric, in a somewhat fleshy perisperm, antitropus. Coiyledones oval, flat ; radicle 

 elongated, curved. — Annuals, with the leaves generally hirsute, nearly all radical ; 

 panicle or branches trichotomous and very divaricate, the ramifications sub- 

 tended by verticillated bractes, free or united, into a cup. Involucres very 

 small, solitary and pedicellate, 4 to .5-toothed, the teeth terminating in very long, 

 sharp, rigiil bristles, more rarely unarmed; perianth pubescent; the branches 

 clothed with viscid, pedicellate glands. Somewhat allied to Chorizanthe, but 

 with the involucrum more than l-flowered, and the achenium compressed. 



fFrom the singular prostrate, thread-like stem. 

 J In allusion to the peculiar involucrum 



