The Rosidae
Family Overview - The Rosales
Rosaceae - the Rose Family
Diversity:  Herbs, shrubs, and trees in about 100 genera and over 3,000 species with highest diversity in northern, temperate parts of the world  Important commercially as a source of ornamentals (Rosa), and various domesticated fruit crops that are mostly of Eurasian origin [apples (Malus), pears (Pyrus), cherry, peach, almond  (Prunus), strawberry (Fragaria) and blackberry, raspberry (Rubus)].

Distribution:  Worldwide, but mostly in the northern hemisphere.  We have 25 genera with 108 species in Texas, including many common, conspicuous, and early-blooming inhabitants of the local flora.

Floral structure:

 Significant features:  Leaves of varying type but often alternate with stipules.  Flowers with a distinctive suite of features in the androperianth that is carried by most genera:  pentamerous perianth, numerous stamens, and a hypanthium.  Variation at the subfamily level is based on the gynoecium, as indicated above.
 
 
 

  Physocarpus opulifolius (Spiraeoideae) - perigynous flowers at anthesis (left) and in fruit (right - follicle)


Rubus trivalis (local dewberry)(Rosoideae) - flower at anthesis (left) and in aggregate fruit (right) and domesticated red raspberry with calyx, receptacle, and aggregated druplets (far right)

 
  Geum canadense (Rosoideae) - flower at anthesis (left) and in aggregate fruit (right).  True fruit is an achene with a hook

 Prunus (Prunoideae) - front view of flower at anthesis (1), side view with hypanthium removed (2 - from UH Botany), P. mexicana (local species currently in bloom) gynoecium at anthesis (3) and with ovary fully mature (4  = 'Mexican Plum') to produce a drupe
 
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 Pyrus (Maloideae) - front view of flower at anthesis (1), side view (2) (note pedicel, position of the ovary, and calyx). Mature pome of Crataegus (3 - local hawthorne - note pedicel, ovary, and calyx), and cross section of Malus (4 - apple) pome with a five loculate ovary separated from the hypanthium by a dim green line near the outside edge of the locules - see pome overview  

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More information on the Rosaceae


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