6i8 
U'lRICULARIA 
Utricularia Linn. Lentibulariaceae. 200 sp. trop. and temp., the latter 
all aquatic. 3 in Brit. ; the commonest is U. vulgaris L., the 
bladder-wort. The morphology of U. is very interesting, for the usual 
distinctions drawn between root, stem and leaf cannot be applied here. 
The common bladder-wort is a submerged water plant with finely- 
divided leaves ; it never has any roots, even in the embryo. The 
firs, project above the water on short shoots, and there are also short 
shoots with small leaves, which arise from the main axis and grow 
upwards to the water surface. Upon the ordinary submerged leaves 
are borne the bladders, curious hollow structures with trap-door 
entrances. Small Crustacea and other animals push their way into 
the bladders and are not able to escape, for the doors only open from 
outside. The plant takes up the products of the decay of the 
organisms thus captured ; it is very doubtful whether any special 
ferment is secreted (p. 177). Other sp. of U. are land plants with 
peculiar runners, which develope in the moss or other substratum, on 
which they grow, and there bear the bladders. Others again, e.g. U. 
montana Poir., are epiphytes with water storage in tuberous branches. 
The leaves of all these forms are simple. Goebel (Pdanzendiol. Sch.) 
has investigated the development of U. and finds that all these parts — 
leaves, bladders, runners, water-shoots, erect shoots, &c. — are practically 
equivalent to one another, and that the same rudiment at the growing 
point may give rise to any one of them, or that they may themselves 
change from one to another type. Similarly on germination a lot of 
spirally- arranged primary leaves are produced, and then one or two 
water-shoots appear laterally on the growing point, bearing no direct 
relation to the leaves in position, but apparently homologous with 
them. “Like Genlisea, U. possessed originally a leaf-rosette, ending 
with an infl., and consisting partly of bladders. Then were added 
the swimming water-shoots or (in land forms) runners, which though 
externally unlike leaves (since they develope indefinitely and produce 
leaves and infls.) yet are originally homologous with them.” For 
further details see Goebel, loc . cit. 
Uvaria Linn. Anonaceae (2). 60 sp. Indo-mal. Mostly lianes with re- 
curved hooks (infl. -axes). The connective of the anther is usually leafy. 
Vaccaria Medic. = Saponaria Linn. 
Vacciniaceae (Benth. -Hooker) = Ericaceae (§ in Vaccinioideae). 
Vaccinium Linn. (incl. Oxycoccus Tourn.). Ericaceae (in. 7). 120 sp. 
N. Hemisph. There are 4 sp. in Brit. V. Myrtillus L. the Whortle-, 
Bil- or Blae-berry, is extremely common in hilly districts. V. uligi- 
nosum L. is like it, but is found only at high levels. Both these have 
deciduous leaves and blue berries. V. Vitis-Idaea L., the Cow- or 
Whimberry (often called Cranberry by error), is also a mountain sp. 
and evergreen. V. Oxycoccus L., the Cranberry, is found in moun- 
tain bogs and is a trailing evergreen with leaf edges rolled back 
(p. 183). The firs, resemble those of Erica, both in structure and 
