Growth, reproductive phenology, and population structure in Syntrichia caninervis
Syntrichia caninervis is a dioicous bryophyte of the arid Southwest. It exhibits a phenology and growth rate similar to the related species Tortula inermis. Mean growth rate was 0.29 mm +/- 0.04 (mean and S.D.). Expressing stems had a significantly greater growth rate than non-expressing stems, but no difference was detectable between males and females. The pattern of gametangial maturation is one of rapid perichaetial development, initiating in September and becoming receptive in March; and protracted perigonial development, initiating in October, developing to an immature state prior to over-summering, and completing maturation during the second fall and spring, with sperm dispersal from February to May. Abortion of gametangia is high ( &j0; + , 42--50%; &j0; ↗ , 20--33%) and most likely linked to low levels of precipitation. Sporophyte maturation was unable to be effectively monitored due to a 100% abortion rate. The ratio of females to males was (2 &j0; + :1 &j0; ↗ ) in the 43% of stems that expressed. Spatial patterning of the sexes is significant, but segregation values were low.
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