. The orchids of New England; a popular monograph. Orchids. THE ORCHIDS OF NE W ENGLAND. 59 the top of the short column, opens in the bud. When the flower is fully expanded, the pollen-masses are left quite free, supported behind by the anther cells, and lying in front against the concave back of the rostellum, with their upper pointed ends resting on its crest. Each pollen-mass is almost divided into two. The few elastic threads of the grains are weak, and large masses of pollen can be broken off easily. The lip has two basal lobes which curve up on each side, and these would com- pel an inse
. The orchids of New England; a popular monograph. Orchids. THE ORCHIDS OF NE W ENGLAND. 59 the top of the short column, opens in the bud. When the flower is fully expanded, the pollen-masses are left quite free, supported behind by the anther cells, and lying in front against the concave back of the rostellum, with their upper pointed ends resting on its crest. Each pollen-mass is almost divided into two. The few elastic threads of the grains are weak, and large masses of pollen can be broken off easily. The lip has two basal lobes which curve up on each side, and these would com- pel an insect to approach the rostellum straight in front. As. Fig. 16.—Listera ovata. {From Muller.) i. Side view of unfertilized flower: ov, ovary. 2. Front view, after the pollen-masses, po, have been removed from the anther. The flat rostellum (r) is bent forward and partly conceals the stigma (si). (Magnified one-half as much .as i.) «, nectary. 3. Pollen-masses adhering to a needle (greatly enlarged), c, cement. 4. Grammoptera loevis, with a number of pollen-masses on its head. soon as the flower opens, if the exquisitely sensitive rostellum be touched ever so lightly, a large drop of viscid fluid is instan- taneously expelled, and, oil exposure to the air, in two or three seconds the drop sets hard, soon assuming a purplish brownish tint. As the pointed tips of the pollen-masses lie on the crest of the rostellum, they are always caught by the exploded ; This drop, then, does the work of a viscid disc for the pollen- masses. " When the anther-cells open, the rostellum slowly curves over the stigmatic surface, so that its explosive crest stands at a little distance from the summit of the anther; and this is very necessary, otherwise the summit would be caught by the viscid. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly res
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Keywords: ., bookcentury1800, bookdecade1880, bookpublishernewyo, bookyear1884
