247 
BOTANICAL NOTES. 
By Dr. GEORGE VasSEY, BOTANIST. 
FERTILIZATION OF WHEAT AND OTHER GRASSES.—In the monthly 
report of this Department for October last is an article by the Commis- 
sioner on the “Cultivation and hybridizing of wheat,” in which are 
given the results of some observations made by his direction, which 
results coufirmed his opinion that the fertilization of wheat was effected 
in the closed flower, and hence that hybridization does not naturally 
occur between different varieties growing in close proximity. This gub- 
ject. in its reference not only to wheat but to other grasses, appears to 
have also received some attention in Germany, particularly by Professor 
Hildebrand, of Frieburg, and is made the subject of a paper read by 
him before the Berlin Academy of Sciences, October 31, 1872. 
A brief synopsis of this paper, from a translation published in the 
(London) Gardener’s Chronicle and Agricultural Gazette, is as follows: 
With respect to their floral structure grasses may be classified under 
the following heads: 
1. Diecious grasses.—Here, the two kinds of floral organs, viz, stamens 
and pistils, grow on distinct plants, one portion producing only stami- 
nate flowers, and the other portion producing only pistillate flowers. 
There is but a small number of species of this class. The buffalo-grass 
of the plains (Buchle dactyloides) is one of them. 
2. Monecious grasses.—In this class the staminate and pistillate flowers 
occupy different parts of the same plant. In Indian corn (Zea mays) the 
staminate flowers occupy the summit of the plant, while the pistillate 
are arranged upon an axis proceeding from a lower portion of the plant. 
In wild rice, (Zizania aquatica) the fertile flowers occupy the upper part 
of the panicle, and the staminate flowers the lower part. 
3. Polygamous grasses——Here a portion of the flowers may be perfect, 
that is, combining both sexes, and a portion will be either wholly stam- 
inate or wholly pistillate. Some species of Panicum and of Andropogon 
are of this description. 
4, Perfectly flowered grasses.—This ineludes the larger portion of 
grasses, especially of temperate climates. In this division fall also 
most of our cultivated grains, as wheat, oats, and barley. 
In grasses of the first class, 7. e., dicecious grasses, the pistillate flowers 
must necessarily be fertilized by the pollen from entirely distinct plants, 
just as among higher plants the pistillate willow is fertilized by the pollen 
from the male willow of the same kind but on a different tree. On the 
western plains where the buffalo-grass prevails, large patches may be 
found having only male flowers, and other patches occur having only 
female flowers. The seed of course is only produced upon these female 
or fertile plants. Until this fact was discovered, the two sexes were 
supposed to be different species, and were known by different names. 
In the moneecious grasses also, as in the common Indian corn, (Zea 
mays,) the pistillate flowers must be fertilized from without; the pistils are 
thrust out from the husky covering and exposed to the influence of any 
pollen which may fall upon them; hence the readiness with which, dif- 
ferent varieties, if planted in proximity, hybridize or mix with each 
other. The same is true to a large extent with polygamous grasses. 
In the case of the perfectly flowered grasses, we find several provis- 
ions existing, which affect the mode of fertilization. 
