SIGNS AND ABBREVIATIONS. 
XXXIX 
248. Suborders are divisions of orders, of the highest rank ; they are to 
orders what subgenera are to genera (235). Their names are formed like 
those of orders, but without the termination in acece, when that can be 
avoided. 
249. Tribes are sections of orders of lower rank than suborders, and 
are named in a similar way, as Tribe Clematideje, and the rest, under 
the Order Ranunculaceae, p. 2. (See also Rosaceae, p. 112, both for sub¬ 
orders and tribes.) In the larger families Sw5tribes are introduced, as 
divisions of a still lower grade than tribes. 
250. To assist the learner in practically arriving at the leading character¬ 
istics of the orders, while ascertaining the order to which an unknown 
plant belongs, an artificial analytical key to the orders is appended 
(p. lxviii.). 
251. The object of an artificial classification (240) is to furnish a con¬ 
venient mode for ascertaining the genus and name of an unknown plant, 
by the use of whatever set of characters will most readily answer the pur¬ 
pose, without regard to their relative importance, or to any agreement in 
other respects. 
252. The only Artificial System which has attained a general celebrity 
and currency is that founded by Linmeus, on the number, proportion, po¬ 
sition, &c., of the stamens and pistils ; the classes upon the stamens, and 
the orders in great part upon the pistils. It is therefore employed as the 
basis of the extended Artificial Key to the Genera comprised in this work ; 
a tabular synopsis of the classes being prefixed (p. lii.). 
* # # Signs used in this Work. 
(T) An annual plant. 
® A biennial plant. 
A perennial plant. 
? A mark of doubt. 
! A mark of affirmation or authentication. 
1°, 2', 3". To save space, the signs of degrees (°) are used for feet; 
of minutes (') for inches; of seconds (") for lines, a line being the 
twelfth part of an inch. 
The following signs are common, but have not been used in this 
work, viz : — g A staminate plant or flower: $ A pistillate plant 
or flower : and $ A perfect flower, or a plant that bears them. 
Principal Abbreviations of the Names of Authors. 
Adans. 
— Adanson. 
Beauv. = 
Palisot de Beauvois. 
Mt. 
Aiton. 
Benth. 
Bentham. 
Andr. 
Andrews. 
Bernh. 
Bernhardi. 
Am. 
Arnott. 
Bieh. 
Bieberstein. 
Auct. 
(auctorum), of au- 
Bigel. 
Bigelow. 
Aubl. 
Aublet. [thors. 
Brid . 
Bride!. 
Bart. 
Barton. 
Brongn. 
Brongniart. 
Bartl. 
Bartling. 
Cass. 
Cassini. 
