This inflorescence of 'Pat Ballard' tassel bush (or silk tassel) is not fully developed – hints of flowers emerging from behind the bracts can be imagined, but the reason for the common name is not readily apparent from this image. Instead, please see the University of California Botanical Garden's page on Californian waterwise plants for the flowers of the male parent of this hybrid. For close-ups of the flower, you can see some nifty SEM (scanning electron microscope) images in a paper on Garrya floral morphology (note: PDF): Liston, A. 2003. A new interpretation of floral morphology in Garrya (Garryaceae) . Taxon. 52:271-276. The paper goes into great detail on the structure of the flowers and how misinterpretations of the floral morphology have hampered understanding of the evolutionary relationships.
For a horticultural perspective on the plant, including the origin of its name, please see Bellevue Botanical Garden's Plant of the Month entry for it. The site doesn't allow direct linking to taxon pages, so you'll have to scroll down and find the entry.
Botany resource link: Considering collecting plant specimens for your local herbarium? A tidy “how-to” guide with tips on collecting and preserving can be found here: Field Techniques Used by Missouri Botanical Garden.