[27]

Monocot. Plants

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Dicots & Monocots together

(V Last Calc.)

[calculations not transcribed]

10.00 average species to genus in those genera which have 1 or more species with vars.

If we leave out Carex (with 126 sp the result is 8.3 → That is one.

If we leave out all Salix with 22 species the result is 8.09

If we leave out Carex, Aster & Solidago, the largest genera the result is 7.5 per genus.

(Now in U.S of all Dicots the average species per genus is only 2.68. for monocots 3.65, (without Carex it is 2.86)

For both Monocot & Dicot it is 2.90 species per genus

So that clearly the it is the large genera which present varieties. And judging from Compositæ it is the large Families which vary most.

For both Mono & Dicot. together omitting Carex with 126 sp the average for each genus is 2.72. (or 2.70 with Salix also omitted.

There are only 10 genera out from the 68 which have 2 or more species with vars.

These 10 have 104 species, or on average 10.40 to genus (carex & salix omitted). The grand average, with same omissions, for whole manual; genera with single species being omitted, is only 4.67. But as these are only 10 genera, the result of not much value.

Used

[27v]

Dr. A. Gray's manual. Genera which have one or more species presenting varieties. I have counted those vars which are either named or numbered, & in a few instances vars. described but not named or enumerated Several plants are said to be very variable in this or that point, but are not said to present distinct vars. The number of X show how many species in the Genus have vars. —

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