Grafting growth in the vascular cambium. Occasionally, a so-called "graft hybrid" or more accurately graft chimera can occur where the tissues of the stock continue to grow within the scion. Such a plant can produce flowers and foliage typical of both plants as well as shoots intermediate between the two. The best-known example this is probably +"Laburnocytisus" 'Adamii', a graft hybrid between "Laburnum" and "Cytisus", which originated in a nursery near Paris, France in 1825. This small tree bears yellow flowers typical of "Laburnum anagyroides", purple flowers typical of "Cytisus purpureus" and curious coppery-pink flowers that show characteristics of both "parents".
Laburnum Avenue an at-grade crossing of Norfolk Southern Railway's Richmond District rail line and intersects SR 33 (Nine Mile Road) west of Highland Springs and east of the historic home Beth Elon. The highway heads north, intersecting Creighton Road, then curves west and intersects US 360 (Mechanicsville Turnpike) within East Highland Park. Laburnum Avenue crosses over CSX's Piedmont Subdivision and passes along the southern edge of Richmond International Raceway between Carolina Avenue and Richmond Henrico Turnpike. Laburnum Avenue continues west into the city of Richmond. The four-lane boulevard intersects US 1 and US 301 (Chamberlayne Avenue) within the Ginter Park Historic District.