Three New Species of Impatiens L. from China and Vietnam: Preparation of Flowers and Morphology of Pollen and Seeds

The genus Impatiens (Balsaminaceae) is one of the most difficult genera for making effective herbarium specimens because of its tender and complicated flowers. The preparation of flowers is always one of the most important steps in the collections of Impatiens. The present paper demonstrates a method to prepare flowering specimens of Impatiens in the field. Examples include three new species collected from the Sino-Vietnamese border, viz. Impatiens aconitoides , I. purpureifolia , and I. rugata . The related species I. laojunshanensis, I. apalophylla, and I. clavigera are also sampled using the same preparation method. As to the three new species, their pollen grains and seeds were observed by scanning electron microscopy. Impatiens aconitoides has 4-colpate pollen grains and ovoid seeds with protrusive-type of seed coat, whereas I. purpureifolia and I. rugata have 3-colpate grains and ellipsoidal seeds with reticulate-typed seed coat. Such an integrated approach to include detailed floral characters as well as pollen and seed characters is proposed when new taxa of Impatiens are described.