Tree Morning Glory
Here are photos of Tree Morning Glory (Ipomea carnea). The flowers are large and sort of a pink-lavender color. It's common in the barrios of Mexico and is also known as Diez en la Manana because the flowers usually close by 10 in the morning. The seeds are fuzzy and sometimes are called "kitty toes".
I agree the "tree" part of the name is a little misleading as this plant seldom reaches more than 10 feet tall here in the low desert. Our frosts and freezes keep its size in check. Sometimes the shoots will die back as much as 2 -3 feet but the plant grows back as soon as the weather warms again in the spring.
Some nurseries carry this plant and I believe seeds were for sale at the last Fall Garden Festival put on by the U of A Master Gardeners.