Ceratophyllum.'] i.xxx. urticace.e. 
389 
Frequent in slow streams, ditches, and canals. y. 6 , 7. — 
Floating. Stem long, slender. Leaves 2 or 3 times forked, distantly 
serrate. Flowers small, axillary. Our var. a. is the only one yet 
observed in this country ; / 8 . is the most common in Germany, and 
may have been passed over with us as the same as a. 
2. C. submersum L. ( unarmed H.) ; acliene without spines 
near the base terminated by the usually short style. — a. fruit 
without 2 conspicuous tubercles at the base, style very short. 
E. B. t. 679. C. muticum Cham. — 0.* fruit without 2 con- 
spicuous tubercles at the base, style elongated. C. muricatum 
Cham. — y* fruit with two tubercles at the basS otherwise 
smooth, style elongated. C. submersum DC. C. apiculatum 
Cham. 
Ditches in the east and south of England, rare. y. 6, 7. — 
Mr. Babington states that the ripe fruit of var. a. is covered with 
tubercles; in our /3., according to Chamisso, it is similar. As far as 
we know, neither /3. nor 7 . have been found in this country; but as 
this species very seldom bears flowers or fruit, it and its varieties can 
rarely be distinguished. The var. 7 . connects this with the last 
species ; so that, taking also into consideration the great variation to 
which aquatics are subject in all the organs of vegetation and repro- 
duction, Mr. Betitham is probably correct when he unites the various 
forms of the genus into one species. 
Ord. LXXX. URTICACEiE Juss. 
Flowers generally monoecious or dioecious (very rarely some 
of them perfect), scattered, or amentaceous, or aggregate, on 
a fleshy persistent receptacle. Perianth divided, persistent or 
wanting. Stamens definite, distinct, opposite the lobes of the 
perianth and inserted at its base when there is one. Ovary 
free, 1 -celled. Ovule solitary. Fruit usually an achene, often 
several combined and immersed in the persistent fleshy perianths 
or upon or within large fleshy receptacles. Embryo with the 
radicle superior. — Trees, shrubs, or herbs, with stipules, often 
stinging and sometimes milky . — This has been divided into four 
Orders or Sub-Orders. I. URTicEiE, containing the nettles, &c., 
the fibre of the inner bark of some of which is very tenacious. 
II. Cannabine^e, yielding hemp from the genus Cannabis, and 
a narcotic bitter from the same and also from the hop. III. 
More.® (known by the flowers in heads, spikes, or catkins, 
stamens incurved during aestivation, hooked embryo and fleshy 
albumen) ; to which belong Morus alba, producing the mid- 
berry; M. tinctoria, the dye called fustic ; Broussonetia or the 
paper mulberry. IV. Artocarte/E (having the flowers in 
dense heads, spikes, or catkins, stamens straight during aestiva- 
tion, a very short radicle, milky juice, and almost always alter- 
s 3 
