Perispore Structure in Polystichum setiferum, P. aculeatum and Their Hybrid P. Xbicknellii

Abstract

Polystichunz Xbicknellii (Christ) Hahne, the hybrid between P. aculeatum (L.) Roth and P. setiferum (Forsk.) Woynar, has been found in many European countries (Sleep, 1975). In Spain this hybrid has been mostly found in the Pyrenees, Iberian Ranges, and Cantabrian Ranges (Salvo et al., 1986). Both fertile plants and their hybrid are morphologically close, and can be identified by differences in frond morphology (Fig. 1) and perispore pattern (Sleep, 1971, 1975; Salvo et al., 1986). Plants of P. setiferum, P. aculeatum and P. Xbicknellii were found growing together in the Spanish Central Pyrenees, thus giving a good opportunity to study the influence of both parents on the hybrid's spore morphology (structure and external morphology of the perispore). The plants are from: Huesca, Cai6n de Aiisclo, 750 m, growing in a beechwood on base-rich soil, 24.6.1987, leg. Fernandez Gonzalez et al. Voucher specimens are kept in the Herbarium of the Faculty of Pharmacy, Universidad Complutense, Madrid (P. setiferum, MAF 135851; P. aculeatum, MAF 135852; P. Xbicknellii, MAF 135853). Spores of the three specimens were suspended in water and cut by means of a freezing microtome following the method of Muller (1973). Sections were transferred to slides and mounted in gum chloral for light microscopy observations, and air dried, mounted on an aluminum stub and gold coated for SEM studies. The differences in the perispore morphology of P. setiferum and P. aculeatum reflect the different structures of their spore wall. The spores of P. setiferum (Fig. 2, A-D) show