By skyforbes 
Look Alikes
Close relative black raspberry (Rubus occidentalis) grows in eastern North America, from Quebec and Ontario, west to Colorado, south to Georgia, and all along the eastern seaboard of the US. Blackberries (Rubus spp.) are yet another species, found across all of North America.
Black raspberry plants look very similar to those of red raspberry, but careful observation can discern the two. Black raspberry leaves are typically composed of three leaflets, rarely five. They can be pinnately compound like red raspberry, or palmately compound (like fingers coming from a palm.) Like red raspberry, the leaflets are silvery underneath. More obvious differences are found in the stems, which are strongly arching and readily root at the tip. They are also more heavily armed than red raspberry, with straight or recurved thorns.
Blackberry plants can also be confused with red raspberry, but they can be readily distinguished by the leaves and stems. Blackberry leaves are always palmately compound, with 3 to 7 leaflets, typically 5. The leaflet undersides are light green, not silvery. The canes tend to grow upright, and are heavily armed with straight or recurved thorns.
Harvest and Use
Red raspberry leaves are best harvested before the plant flowers. Pick with thick gloves to protect your hands from the sharp bristles, or use a scissor. If the canes are sparsely armed, you can use bare hands.