Sentence Examples


  • The female flower is enveloped in a closely fitting sac-like investment, which must be regarded as a perianth; within this is an orthotropous ovule surrounded by a single integument prolonged upwards as a beak-like micropyle.
  • The whole flower may be looked upon as an adventitious bud bearing two pairs of leaves; each pair becomes concrescent and forms a perianth, the apex of the shoot being converted into an orthotropous ovule.
  • - Orthotropous ovule of Polygonum in section, showing the embryo-sac s, in the nucellus n, the different ovular coverings, the base of the nucellus or chalaza ch, and the apex of the ovule with its micropyle m.
  • Isolated fossil seeds are common in the Carboniferous and Permian strata; in all cases they are of the orthotropous type, and resemble the seeds of Cycads or Ginkgo more nearly than those of any other living plants.
  • As a rule, however, the fossil stems show a marked difference from modern forms in the possession of lateral shoots given off from the axils of leaves, and terminating in a flower of complex structure containing numerous orthotropous seeds.