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Il. Botanical description of the natural order Leguminosae. 
The leaves of leguminous plants are usually alternate, and arranged spirally round the stem; very 
rarely, they are, as in grasses, alternate and two-rowed. The leaf consists usually of a distinct stalk 
or petiole, and a compound blade formed of several portions distinct from one another — the leaflets. 
If there are three leaflets, as in clover, the blade is trifoliate; if several leaflets are arranged along 
opposite sides of a midrib, pinnate, either pari-pinnate e.g. vetches, or impari-pinnate e.g. sain- 
foin (PI. XY) according as an even or odd number of leaflets is BESSCats When the leaf is pari-pinnate, 
the midrib often ends in a tendril, e.g. vetches. 
At the base of the petiole a pair of lateral outgrowths, the stipules, always occur. The stipules 
are either membranous or herbaceous ; they are attached to the stem by a broad base (free), and often 
also to the petiole (adnate). 
The inflorescence is either a raceme, a simple wmbel, or a capitulum. Its position is either terminal, 
at the end of a leaf-bearing stem or branch, or /ateral, springing from the axil of a leaf. 
Each flower is always hermaphrodite and complete, i. e. it is composed of a calyx, corolla, stamens 
and pistil. It is irregular i. e. the parts in the same whorl are unequal in size, forming a_ bilaterally 
symmetrical structure. A regular flower such as a Tulip, is radially symmetrical, and has the parts equal 
in size; its perianth is composed of six equal and symmetrical parts. 
The calyx is formed of five sepals cohering at the base and terminated by teeth, which are 
often long and acute. Usually it is irregular, as one of the teeth is longer than the others. The long 
tooth lies in the median line, on the lower face of the flower, next the bract; it is technically spoken 
of as the anterior tooth, e.g. Red clover (Pl. XII, Fig. 4). 
The corolla is composed of five petals, unequal in size, and free from one another, except in 
Clovers. The largest petal is the standard (vexillum); it lies between the two superior teeth of the 
calyx; the broad terminal portion — the limb — is usually bent upwards and notched at its apex 
(emarginate). Right and left of the standard, lie the wings (alae), which partially overlap the keel. The 
keel (carina) is composed of two petals usually cohering more or less by their lower margins; this 
pair of petals lies right and left of the lower (anterior) calyx tooth (Fig. 6). In the bud, the keel is 
overlapped by the wings, and the wings by the folded standard. 
The Stamens are ten; usually the nine lower cohere for a considerable part of their length by 
their filaments, so as to form a tube, split superiorly and surrounding the pistil. The tenth stamen 
fills up the slit in the tube. The anthers lie concealed in the apex of the keel. 
The pistil consists of a one-chambered ovary containing one or more ovules, attached along the 
ventral suture, 1. e. the margin of the pistil which is directed towards the standard. The ovary is pro- 
longed into a long style. which is curved upwards, and terminated by a single stigma of variable form. 
Two posterior Calyx Teeth The annexed diagram of a papillionaceous flower (Fig. 6) 
Shows at a glance the whole floral structure. 
Standard 2 ee As already explained, the pollen of grasses is easily shaken 
out from the open anthers, and is carried by the wind to the 
Wing Fane stigmas — wind fertilization. In Leguminous plants the arran- 
a gement is quite different. The pollen requires, for its trans- 
eee port, the aid of insects, which come to the flower in search 
React of honey or pollen; these insects convey the pollen to the 
Fig. 6. Diagram of a Leguminous flower stigmas — insect fertilization, As will be explained in the 
(after Eichler). special part, the arrangements for securing the attachment of 
2 
Leaves. 
Inflorescence. 
Flower. 
Fertilization. 
