398 PATAGONIAN EXPEDITIONS I BOTANY. 



S. Patagon., by mouth of Rio Gallegos, and by Lago Argentine. 

 This plant when fresh is green and scentless ; when dry it emits a strong 

 scent like that of Valerian. (Speg.) 



Family 38. CERATOPHYLLACE.E. Hornwort Family. 



Submerged herbs, with long, leafy branches, having whorled, finely dis- 

 sected leaves with filiform segments, and monoecious flowers, solitary, 

 sessile in the axils. Perianth single, many-parted. Stamens numerous, 

 subsessile, extrorse, the connective prolonged. Ovary i -celled, i -seeded. 

 Style i, filiform. 



The fertile and the sterile flowers are generally at different nodes, or 

 at opposite sides of the same node. 



One genus and 4 species, cosmopolitan, but not in arctic or antarctic 

 regions. 



CERATOPHYLLUM Linn. 



Leaves spinulose-serrulate, forked. Male flowers with 10-20 stamens, 

 anthers as long as the perianth. Fruit slightly exceeding the perianth, 

 tipped by the persistent style. 



C. AUSTRALE Griseb. 



Lower leaf-segments narrow-linear, entire ; upper linear-capillary, ser- 

 rulate. Achenes shortly pedicelled, ellipsoid, tuberculate, narrowly repand- 

 marginate, naked at the base. Style persisting, at length elongate. 

 Leaves 3-4 cm. long. 



N. Patagon., Rio Negro. 



Family 39. RANUNCULACE.E. Crowfoot Family. 



Herbs, rarely climbing shrubs, with exstipulate leaves, alternate 

 (except in Clematis], and regular or zygomorphous, complete, or some- 

 times apetalous flowers. Sepals 3-15, not united (in apetalous species 

 mostly petaloid). Petals mostly as many, not united. Stamens numer- 

 ous, they and the perianth-leaves all distinct and hypogynous. Carpels 

 numerous, rarely i or few, nearly always distinct. Fruit having achenes 

 or follicles. Embryo minute in large endosperm. 



Species exceeding 1,000, most in Europe and N. Amer. ; fewer in the 

 tropics. All in the Patagonian Flora have regular flowers. 



