Ontogeny of the pollinium in Hoya carnosa provides new insights into microsporogenesis.

The presence of a pollinium is a distinct character in Apocynaceae which is important for phylogenetic analysis. The pollinium of Hoya has an outer sporopollenin wall and a pellucid margin which are adaptive features. However, their ontogeny and related evolutionary implications are not entirely understood.

Thalli Growth, Propagule Survival, and Integrated Physiological Response to Nitrogen Stress of var. in Shennongjia Mountain (China).

In this study, effects of nitrogen (N) availability on growth, survival of var. , and whether it respond nitrogen stress in an integrated physiological way was evaluated. Thalli growth and propagule survival, thalli N and phosphorus (P) content, and activity of phosphomonoesterase (PME) of var.