Ask Mr. Smarty Plants

Mr. Smarty Plants hates to admit failure, but he hasn't been able to find a photograph of a seedling of Rivina humilis (pigeonberry) either online or in print.  i can offer you three different line drawings of the plant itself from Flora of North America, Flora of China, and Flora of Pakistan and numerous photographs of mature plants.  You can even see a slideshow of photographs from the Atlas of Florida Vascular Plants. You can also find a line drawing in Shinners & Mahler's Illustrated Flora of North Central Texas, p. 885, and see it by downloading the appropriate pages. I did find a link to someone trying to figure out if her tiny plant was a pigeonberry, but there was no conclusion reached about its identification from the respondents who saw her photograph.  And, I did find a drawing of a seedling of Rivina laevis from a book, Seedlings, by Sir John Lubbock, published in London in 1907 and available online through Canadian Libraries.  To find the illustration enter "Rivina" as the search term. There is a seedling database called The Seed Site, but, unfortunately, it doesn't have a photograph of Rivina humilis. There are also numerous weed seedling databases (you can find them by Googling "weed seedling") but none that I found contained Rivina humilis.  So, if you are trying to determine if the tiny plants that are emerging in your garden are R. humilis, my advice would be to compare the first true leaves with those of the youngest leaves on the photos of young and mature plants of the species—then wait to see if it really is pigeonberry.  Certainly, as the plant grows and adds leaves, you will probably be able to tell if you have a pigeonberry or not.