352 THE CROWFOOT FAMILY 
bered as affording other examples already discussed in 
Chapter V. 
104. Plant formulas. We may be helped in summing up what 
we have learned from our various examples if we express their 
most significant structural characteristics by means of symbols 
arranged in a sort of tabular view as on page 353. 
At the beginning of the formulas there given, the signs @, 2, P , 
+, are used respectively for annuals, perennial herbs, woody plants, 
small shrubs, and vines, as already explained (p. 333). A comma indi- 
cates an alternative, and is to be read ‘‘or.”” Thus in the formula 
of Pzonia we have 21,5, reading ‘‘perennial herbs or low shrubs.” 
These signs since they apply to the plants as a whole come first in 
the formula. The letters which follow stand for various parts: 
L for leaves; u, leaflets; I, inflorescence; i, secondary inflorescence; 
B, bracts; b, bractlets; S, sepals; P, petals; FA, stamens (filaments 
with anthers) ; F, staminodes (filaments without anthers) ; CE, carpels 
(carpellary leaves with ovules, 7. e., egg-sac members); E, ovules 
well developed; e, rudimentary ovules; T, torus; C, carpels ripened 
into pericarps; £, seeds; G, embryo (germ); V, albumen (nutriment). 
When the leaves are alternate, as in all the genera except Clematis, 
this is expressed by L1/; which signifies that there is a single leaf at 
each internode. In the exception noted L2/. means that the leaves 
are opposite, ¢. e., two at a node. Palmate nervation is shown by 
the asterisk *, ternate by the dagger sign 7, and pinnate by the 
double dagger {, which, as will be noticed, suggest by their form the 
arrangement of nerves they each represent. That a leaf is com- 
pound is implied by the presence of leaflets indicated by the small x. 
In the formulas of Anemone and Clematis this shows that the 
leaves are but once-compound, while in the Pzonia formula L'* 
means that the leaves are once to thrice-compound, while L?+ in the 
Aquilegia and Actzea formulas stands for decompound. 
When the inflorescence is of the indeterminate type an inverted 
comma follows the I as in the Aconitum and Actza formulas; and 
when of the determinate type, as in the other examples, an inverted 
period is used. A solitary terminal flower, as in Pzeonia and Nigella, 
is indicated by I'l. Where, as in Caltha, Anemone, and Clematis, 
additional flowers may appear forming a cymose cluster, I°1 + is 
used. When the plant has only solitary axillary flowers like Myo- 
surus the expression becomes I‘1. A cymose corymb, as of Aquilegia, 
is represented by I°’/; while a raceme of the botryose type, as in 
Aconitum and Actza, has I“, the short and the long oblique lines 
standing respectively for short and long pedicels. The presence of 
a small i, as in the formula of Clematis, implies a compound cluster. 
In this case it is shown to be of paniculate form because of the 
relatively short pedicels. Where the type and form of inflorescence 
varies as in Ranunculus, their special signs may be omitted. The 
