Excerpts from Jim Conrad's
Naturalist
Newsletter
from the April 9, 2017 Newsletter, a special on-the-road edition with notes from Calhoun, rural western Kentucky, USA
PAWPAWS FLOWERING
At http://www.backyardnature.net/n/w/pawpaw2.htm we've looked at southern Mississippi's Small-flowered Pawpaw tree, Asimina parviflora, and its delicious, mid-summer-ripening fruits. In the swamp next to my aunt's house in Calhoun, nowadays the nearly identical small trees known just as Pawpaws, ASIMINA TRILOBA, are flowering. Below, you can see a flower and a flower bud on a leafless Pawpaw stem in my hand:
Notice that the flowers have three sepals -- an unusual number for a flowering dicot -- and that the sepals are covered with short, rusty-colored hairs. Also a little unusual is that the corolla consists of six petals arranged in two "whorls," each whorl of three petals. Petals of the inner whorl are 1/3 to 1/2 the length of petals of the outer whorl. Inside the corolla the whitish, spherical item is composed of many spirally arranged, immature stamens. A flower close-up, provided just so we can feast our eyes on the petals' rich maroon color and their elegant wrinkles, is shown below:
Pawpaws are members of the Custard Apple Family, along with trees producing such delicious tropical fruits as the Sweetsop, Guanábana and Cherimoya. A few weeks ago in the Yucatan we looked a Guanábana flower broken open to show the anatomy. You can see how similar the structure of that flower was to our PawPaw flower at http://www.backyardnature.net/n/17/170108gx.jpg.