Tuesday, June 21, 2011 ~ News Plant of the Month
Plant of the Month - Raspberries
Blackberries and Raspberries, often termed “Brambles”, are a diverse group of species and hybrids in the genus Rubus. They are members of the Rosaceae family, closely related to strawberry in the subfamily Rosoideae. Rubus is one of the most diverse genera of flowering plants in the world, consisting of 12 subgenera, some with hundreds of species.
Blackberry - “Rubus spp.” is the best approximation to a scientific name, considering that blackberry may be the most taxonomically complex of any fruit crop. R. ursinus Cham. & Schlect. is native to the Pacific Northwest, and has been useful in producing commercial cultivars grown in that region. In Europe, there are 6 species in the Moriferi section that have been used to produce cultivars of local importance; they are referred to as the aggregate species R. fruticosus L. agg.
Red Raspberry - R. idaeus L. The European subspecies of this group is designated R. idaeus subsp. vulgatus Arrhen., whereas the North American red raspberry is termed R. idaeus subsp. strigosus Michx., or more simply R. idaeus (European) and R. strigosus (North American).
Black Raspberry - R. occidentalis L. This is fairly straight-forward, being a good species of its own. Its range overlaps that of R. strigosus, but extends further to the south.
The distinction between blackberries and raspberries revolves around fruit characteristics. All bramble fruits are aggregate fruits, which means they are formed by the aggregation of several smaller fruits, called drupelets. The drupelets are all attached to a structure called the receptacle, which is the fibrous central core of the fruit. In raspberries, the receptacle remains with the plant when fruit are picked, creating the hollow appearance of the harvested fruit. In blackberry, the drupelets remain attached to the receptacle, which comes off with the fruit when picked. A second distinction - raspberry drupelets are hairy and adhere to one-another, whereas blackberry drupelets are hairless and smooth.