Page:Popular Science Monthly Volume 78.djvu/16

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PSM V78 D016 Agave pistils.png
Fig. 11. Early in the Morning. Fig. 12. The next Morning.

longer than the perianth and its stigma is not receptive for pollen. By the next morning, however, the style has reached the stamen in length, though it is still unreceptive. After two days, the stamens have shriveled and drawn out of the way and the stigmatic lines have become fleecy and moist, indicating receptivity. Though scentless, and greenish white, rather than brightly colored, the flowers secrete an abundance of nectar which with the proterandry points to cross pollination by the aid of insects.

When Arthur Schott collected the type specimens of Agave parviflora it was in fruit, though the upper part of some of the specimens still retained a few unopened buds, and a few sterile, dried-up flowers were included in the collection. My own observation of the plant in the field was also made during its fruiting season and I am not aware that its fresh flowers have ever been seen except on this specimen. The main structural characters of the flowers were accurately made out by Engelmann and are preserved in his perfectly prepared dissections, but the contribution which this little specimen has made to a correct understanding of their shape and proportions is clearly shown by a comparison of these type flowers with its own.

Almost if not quite as small as Agave parviflora are two other species in many respects closely similar to it: a little plant found in northern Mexico on the Lumholtz expedition, which Mr. Watson named, after its discoverer. Agave Hartmani, and an unnamed plant of similar habit but with a short perianth tube equalled in length by the perianth lobes, which Professor Tourney found eighteen years ago