Pronephrium
Content
Description
Plants with a frond-form intermediate between P. granulosum and P. rhombeum, with pinnae of irregular shape;
Notes
These plants look like a hybrid swarm, which needs experimental cytotaxonomic in- vestigation. The type collection of P. granulosum includes a frond with one pinna dilated and deeply lobed at the apex, indicating perhaps a slight degree of hybridity. Both parent species have very similar indusia; the sporangia of P. granulosum have glands on sporangia, but the hybrids do not. I have regarded this as an important distinction.
The type of D. xiphioides is the only specimen seen in which no pinnae are dilated distally.
The type of D. xiphioides is the only specimen seen in which no pinnae are dilated distally.