SIGNS USED IN THIS WORK.

°, ´,´´ . The sign of degrees (°) is used for feet; of minutes (´), for inches; of seconds (´´), for lines,—the line being the twelfth part of an inch, and very nearly equivalent to two millimetres.

µ. In microscopic measurements, the conventional sign for the micromillimetre or the one-thousandth part of a millimetre = one two-thousandth part of a line.

♂ Bearing only stamens or antheridia.

♀ Pistillate or bearing archegonia.

? A mark of doubt.

! A mark of affirmation or authentication.

Figures or words separated by a short dash (–) indicate the extremes of variation, as "5–10´´ long, few–many-flowered," i.e. varying from 5 to 10 lines in length, and with from few to many flowers.