GARDEN NASTURTIUM. 33 
by which the reproductive whorls mature at different times, is 
called dichogamy,* and flowers exhibiting this particular 
form of it (which is a common feature among a large number 
of ¥ plants) are said to be protandrous{!—.e., their stamens 
mature first. ” 
The ovary is 3-lobed and 3-celled, with a central style 
dividing at the top into three stigmatic branches. Cut the 
ovary vertically and transversely, and notice the single pen- 
dulous ovule in each cell. 
When ripe the 3 carpels, which are indehiscent, fall away 
from one another, and the fruit is therefore termed a 3-partite 
schizocarp. At thisstage the pericarp is more or less spongy 
or corky in consistence, the seeds have a somewhat tough 
testa, and, when opened, exhibit two thick cotyledons, con- 
cealing a short radicle, but having no endosperm. 
(a.) Compare with this the Canary Creeper (Tropcolum canariense). 
Notice the pedate leaves (i.e., shaped like a bird’s foot) with their five 
lobes, and its flowers agrecing in all main points with the preceding, but 
differing considerably in details. 
(o.) Examine the wild Geraniums, of which 
there are 4 species in New Zealand. Note the 
leaves, varying from orbicular in G. molle to 
palmati-partite in G. dissectum (Pl. L., fig. 4); 
the regular flowers, with 5 imbricate sepals, 5 
petals contorted in bud, the 10 stamens arranged 
in two series, and the 5-lobed ovary. This ovary 
is the most distinctive feature of the genus. ; ; 
The 5 carpels are coherent by their inner edges, Fig. 34. Fruit of 
and have their styles prolonged into a beak, Geraniwm — sessili- 
from which circumstance their common name of  lorwm, before sepa- 
Cranesbill is derived, as well as their technical rationofthe carpels 
name Geraniwm (Gr. geranos, a crane). When (with calyx  re- 
ripe, the carpels separate away elastically from moved). 
the base, and each splits up by its ventral 
suture. This is probably connected in some way 
with the distribution of the seed. The seeds 
are exalbuminous, and have thin, folded cotyle- 
dons. (The cultivated Geranium of the gardens 
is a greatly-hybridized plant belonging to the 
genus Pelargonium, and has its flowers always 
more or less irregular, and some of its stamens Fig. 35. Same, after 
without anthers.) the carpels have 
(c.) Various species of Oxalis (one is the separated, 
plant called Shamrock) are to be found in gar- 
dens, and two grow wild in New Zealand. ‘The structure of their 
flowers is not unlike that of Geraniwm. The 8-foliate leaves are 
singularly sensitive. At night each of the leaflets folds on its midrib 
and hangs down in a limp condition from the common petiole. This. 
condition was called by Linneus their sleep. If on a bright warm day, 
while the sun is strong on the plant, you shake it for a few seconds, you 
will find that in about a minute the same limp condition will be assumed. 
* Gr. dicha, in two parts; gamos, union. 
+ Gr. protos, first; andros, of a male, 
