Seed are sometimes sold commercially while still enclosed within the hard wall of the fruit, which must be split open to reach the seed. Different groups of plants have other modifications, the so-called stone fruits (such as the peach) have a hardened fruit layer (the endocarp) fused to and surrounding the actual seed. Nuts are the one-seeded, hard-shelled fruit of some plants with an indehiscent seed, such as an acorn or hazelnut. Seeds are produced in several related groups of plants, and their manner of production distinguishes the angiosperms ("enclosed seeds") from the gymnosperms ("naked seeds"). Angiosperm seeds are produced in
Sub-district VII of Warsaw suburbs (of Armia Krajowa) for advancing soldiers of the 27th Wołyń Division of Armia Krajowa. In September, medical aid was provided for insurgents of the "Kryska group", who succeeded in swimming across Wisła from the Czerniaków bridge-head to the Praga bank of Wisła river. Region V - it covered the Chojnowo forests, which were a place of concentration of the sub-district's units as well as units of the Sub-district IV of Ochota (of Armia Krajowa) and Sub-district V of Mokotów, which failed to perform their military action on their own area. The commander of the Sub-district IV of Ochota lieutenant-colonel Mieczysław Sokołowski pseudonym "Grzymała",