Yellow culms with random green stripes make this bamboo stand out.  The ABS list this with a maximum diameter of 3 inches but my grove has several canes approaching 4 inches in diameter.  The back side of my pond’s dam is completely covered with Robert Young, overhanging the driveway. The culms are often curved at the base and in general aren’t very straight.  They do stay very erect, rarely arching over.  The new canes are light green and slowly change to yellow over the summer.