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this species and ail those of other species of Oenothera examined do not have shorter 
inner integuments. An obturator is absent. 
Megagametophyte and nucellus (Table 3): The archesporium in Onagraceae is rnulti- 
celled, comprising three to five cells. Archesporial cells are usually distinguished 
from somatic cells by their larger size, denser cytoplasm and more prominent nucleus 
(Maheshwari 1950). However, it was very difficult to determine the number of 
archesporial cells, because the difference is not conspicuous between the archesporial 
and the somatic cells. We often confirmed the presence of a multi-celled archesporium 
Figs 3-6. Longitudinal sections of young ovules showing early development of integuments. 
3. Lopezia racemosa. 4. Epilohium canwn subsp. canum. 5. Epilobium concinmim (Boisduvalia siibuinta). 
6. Cayophytum ramosissimum. In contrast to that of most genera (for example, as in Fig. 3), the 
inner integument (ii) of Epilobium and Cayophytum (Figs 4—6) is extremely retarded in early 
development and is much shorter than the outer integument (oi). All scales equal 20 pm. 
