There are several different posts on DG that deal with this, but I decided to find them and post the key points here so they were all together. I hope this answers your questions.
Within PlantFiles we require that all entries meet one of the following criteria:
1) All species must be recognized and cited within the American Horticultural Society or Royal Horticultural Society encyclopedias; Hortus Third, or the Germplasm Resources Information Network (GRIN) database) at ars-grin.gov, the Missouri Botanical Garden's MOBOT.org site, or other standard reference materials or websites.
2) All cultivars must be registered with an International Cultivar Registration Authorities (ICRA) designated registry (if one exists for the genus); or they should be patented or trademarked.
3) Cultivars (and species, subspecies, species crosses, forms and varieties) that cannot meet the second criteria must be widely available on a commercial or passalong basis, with references (citations) in other databases or reference materials. A single reference (especially when it's the hybridizer, eBay seller or vendor) is not adequate to establish the plant's legitimacy.
We use these criteria to make sure PlantFiles can serve as a reliable reference for readers to look up and identify plants. Allowing entries for unnamed seedlings or unverifiable names will undermine the accuracy and overall helpfulness of PlantFiles.
The following abbreviations are used in PlantFiles: We use these so all entries are in the same format which allows the search engine to find all potential entries. If we had some with ssp. and someone searched for subsp., the entries with ssp. wouldn't show up in the search results.
variety = var.
subspecies = subsp.
forma = f.
All entries are limited to ternary (or trinomial) names.
In simpler terms, this means that beyond the species level, separate entries for subspecies, forma, OR varietas are acceptable, but any nomenclature divisions beyond that will be rolled back up into the "parent" trinomial name entry.
I have two tulip trees that are 5 years old and i don't ever have any flowers on them. do all tulip trees have flowers? i have looked on the top and all but never have seen anything. i live in south carolina about 25 miles from augusta, ga.
For future refernce, this type of question should be posted in the Beginning gardeners forum or Plant ID forum. To answer your question, There are at least 45 different plants called Tulip trees . All of them bloom. Most popular is the Tulip Poplar ( Liriodendron tulipifera) http://davesgarden.com/guides/pf/go/1031/. If this is what you have, 5 years is just a sapling, it has a few years to go. The Saucer Magnolia (Magnolia x soulangeana) is also sometimes called the Tulip Tree. http://davesgarden.com/guides/pf/go/2452/ The others are more exotic, but a google of Tulip Trres will alert you to thier actual species.
Well this is probably in the wrong spot.. new at this and don't know where is goes.. The question is What can I plant under pine trees, with lots of needles and roots? There are lots of trees on my property and tree roots all over the place.. Can anyone help me get started?