The more I've studied and cared for American ginseng, the more enthralled and mystified I have become by this small, inobtrusive, slow growing, imperiled, sensitive woodland plant. According to the NH Department of Agriculture, there are only 17 confirmed sites in the state where ginseng grows wild. At each, there are fewer than 80 plants.
I have never seen ginseng growing wild in NH. I have seen it in Vermont. There, the soil is deeper and sweeter than it is here. I suspect that enhances ginseng's ability to survive. Despite it's rarity in NH, the the photos here suggest that the state does have favorable habitat where ginseng can thrive.
A mature plant is evidenced by at least three prongs, a large flower head that rises up above the leaves, and a stem with a length of more than 12 inches from the ground to the base of the prong.

The flowers will develop into berries that hold 2 or three seeds each. They turn red when ripe, usually in September.
Iam 77 years old and have been familiar with gensing since childhood.I have
several stalks of gensing in my garden here in Leslie, Arkansas. One with
four prongs and two with three. Today (8 August 05) I collected well over a
hundred seed from these three stalke. I put the seed in a mesh type bag for
drying and then put them in the freezer for thirty days or so. Then I plant
the seed and have had good luck with the seed coming up the in the spring.
Here in Arkansas it grows wild in most hardwood forests. Especially on the
north facing slopes. I wrote a book titled "Jake The Woodsman" which is on
our website theboydclan.com. Chapter three it titled Hog Cholera,coons and
gensing. You might enjoy reading on a very large patch found in the mid
1930s. Don't think I am trying to sell books here because at present I have
none left. Enjoyed your remarks about a favorite plant of mine. ben
I drink a lot caffè ginseng, it is very good. Try http://www.renshencafe.it