Houstonia longifolia, commonly known as long-leaved bluet or longleaf summer bluet, is a perennial plant in the family Rubiaceae.Gaertner, Joseph. 1788 De Fructibus et Seminibus Plantarum: accedunt seminum centuriae quinque priores cum tabulis Aeneis LXXIX. Stutgardiae, Tubingae 1: 226 It can be found throughout most of the Eastern United States and Canada. It has been reported from every state east of the Mississippi River except Delaware, plus North Dakota, Minnesota, Missouri, Arkansas and Oklahoma, with isolated populations in Kansas and Texas. Also, all Canadian provinces from Quebec to Alberta.Biota of North America Program It prefers upland woods in poor, dry, often sandy soil.
Description It has upright stalks of or sometimes taller, rising from a basal rosette of leaves. The stalks are slender and branching, with small white flowers with 4 petals. The basal rosette of leaves withers away before the flowers bloom, and opposite leaves appear at intervals along the stems. Flowers bloom for about a month in late spring and summer. It prefers full or partial shade and dry or mesic conditions.
Varieties Two varieties are recognized:Kew World Checklist of Selected Plant Families
Houstonia longifolia var. longifolia - From Georgia and Arkansas north to Canada Houstonia longifolia var. tenuifolia (Nutt.) Alph.Wood. - Florida, Georgia, Tennessee, Virginia
References
External links USDA PLANTS Profile Photo of herbarium specimen at Missouri Botanical Garden, isotype of Houstonia longifolia