Ovulate strobili can be recognized in coastal Douglas-fir [Pseudotsuga menziesii (Mirb.) Franco] in July, megaspore mother cells are evident by September-October, and ovules develop the following March. Meiosis takes place during the period of ovule formation. Some evidence is presented for a hypodermal origin of the megaspore mother cell. Details of later development of the ovule and its pollen-collecting mechanism are given.
Document Type: Journal Article
Director of Forestry Research, Weyerhaeuser Company, Centralia, Wash.