11. Measurements, Dimensions, and Quantities:

11.1 All measurements will be metric, but the unit decimeter (dm) is not to be used. For most structures, millimeters are the smallest units to be used (see also paragraph 11.8) (e.g., "anthers 1.2--2 mm"), but for some structures, such as pollen or spores, it may be appropriate to use micrometers (e.g., "pollen 5--10 µm in diam.").

11.2 For single measurements "ca." or "to" will precede the measurement (e.g., "trees ca. 10 m tall" and "ovary to 2 mm"). Single numbers for quantitative characters are often exact so usually will not use "ca." (e.g., "filaments 10").

11.3 When a single measurement is used, the measurement indicates length, unless some other dimension is explicitly stated, and the word "long" will not be added (e.g., "filaments ca. 3 mm" rather than "filaments ca. 3 mm long" but use "stem ca. 5 mm in diam."). In the case of tree diameter use "d.b.h." for diameter at breast height, which is measured at 1.4 m above the base, rather than "diam."

11.4 If a range of measurements is found for a taxon, a double dash will separate the measurements which will be changed to an en-dash during formatting (e.g., "leaf blade 3--5 cm"). However, a single dash is used to separate a numbers from the words they describe (e.g. "style 3--5-lobed").

11.5 Exceptional measurements will be given in parentheses (e.g., "petiole 3--5(--7) cm"). However, do not use parentheses to indicate exceptional conditions for descriptive terms (e.g., do not use "leaf blade lanceolate (to ovate)" but use "leaf blade lanceolate to rarely ovate").

11.6 If two discontinuous states are commonly found in a taxon, the states will be separated by the word "or" rather than a double dash (see also paragraphs 12.6 and 12.7) (e.g., "stamens 5 or 10" and "petals 4 or 5"). Parentheses can also be used to express alternate states where such states are exceptional (e.g., "stamens 5(or 10)" and "style (3 or)4-lobed").

11.7 If both length and width are used, the measurements are given as length times width. For a times sign use a capital X with a space before and after the X (e.g., "leaf blade 4--6 X 1--3 cm" and "sepals ca. 4 X 1 mm"). During formatting, the capital X will be change to a times sign.

11.8 Use units that are appropriate for the scale of the measurements (but see exceptions in paragraphs 11.10 and 11.11). If a measurement would be an integer or an integer plus a decimal fraction at the next higher or lower unit, then the next higher or lower unit will be used. For deciding what units of measurement are to be used, only consider the usual measurement not the exceptional measurement described in paragraph 11.5 (i.e., do not consider the measurements given in parentheses). For single measurement dimensions, transition from one unit of measurement to the next occurs when 10 units are reached (except for the transition from cm to m where the transition is at 100 cm because dm is not used) (e.g., "10 mm" becomes "1 cm"; "12 mm" becomes "1.2 cm"; "0.9 cm" becomes "9 mm"; "100 cm" becomes "1 m"; "120 cm" becomes "1.2 m"; "0.9 m" becomes "90 cm"). However, round off to the first decimal place (but also see elevations in section 19) (e.g., "3.53 cm" becomes "3.5 cm" and "4.15 mm" becomes "4.2 mm").

11.9 When a range is used, apply a mean of the range to the rules stated in paragraph 11.8 (e.g., "8--12 mm" becomes "0.8--1.2 cm"; "7--12 mm" does not change; "0.8--1 cm" becomes "8--10 mm"; "0.5--1.5 cm" does not change).

11.10 When X is used, apply the mean of the stated measurements to the rules stated in paragraph 11.8 (e.g., "8--12 X 9--12 mm" becomes "0.8--1.2 X 0.9--1.2 cm"; "8--12 X 7--12 mm" does not change; "ca. 9 X 5--17 mm" becomes "ca. 0.9 X 0.5--1.7 cm"). However, when X is used and the length and width are more than two orders of magnitude different, use different measurements for the length and width (e.g., use "20--30 cm X 0.5--1 mm" rather than "20--30 X 0.05--0.1 cm").

11.11 For keys the same units must be used for both leads which means that occasionally the rules in paragraph 11.8 are not followed for one of the couplets.

11.12 The following shows additional examples of the style that will be used and will not be used:

ovary (1--)3--5(--6) mm NOT ovary (1--) 3--5 (--6) mm

leaf blade ca. 5 X 1--2 cm NOT leaf blade 5 X 1--2 cm

leaf blade ca. 5 X 2 cm NOT leaf blade ca. 5 X ca. 2 cm

leaf blade 2--5 X ca. 2 cm NOT leaf blade ca. 2--5 X 2 cm

petiole 3.5--7 mm NOT petiole 3.5--7 mm long

trees 10--15 m tall NOT trees 10--15 m

shrubs 30--70 cm tall NOT shrubs 3--7 dm tall

2-lobed NOT bilobed

2-cleft NOT bifid

nutlets 2 or 3 NOT nutlets 2--3

(3 or)4(or 5)-carpellate NOT (3 or) 4 (or 5)carpellate

3--6(or 7)-hooked NOT 3--6 (or 7)-hooked

5(--7)-parted NOT 5--(--7)parted

2(or 3)-lobed OR lobes 2(or 3)

(5 or)6-veined OR veins (5 or)6

4- or 5-valved OR valves 4 or 5

4--6-valved OR valves 4--6

(5--)7-ribbed OR ribs (5--)7

3(--5)-sided OR sides 3(--5)