Holttum had annotated Faden & Evans 70/422 B in 1971 with a new name based on Shimba, but it was never published. He stated ‘apparently nearest to Nephrodium distans Hook. of Madagascar’ (i.e. Christella distans (Hook.) Holttum). Holttum suggested that Thelypteris dentata var. buchananii Schelpe in J. S. Afr. Bot. 31: 265, fig. 1d (1965). Type: Mozambique, Schelpe 5599 BOL (holo.) is a similar hybrid but is beyond the known range of Pneumatopteris afra; recently it has been treated as a species Christella buchananii (Schelpe) J.P.Roux. Similarly Uhlig 1090 (Tanzania, Kilimanjaro, forest above Kibosho, 2900 m, 1901) has venation associated with the hybrid but P. afra does not occur on Kilimanjaro. It might be a hybrid with another species of Pneumatopteris. Ballard noticed the 2–3 pairs of united veins, and unhesitatingly annotated it as ‘ Dryopteris dentata ’. Study of material from Socotra and the type locality, Yemen throws doubt on some of the so called hybrids since two pairs of anastomosing veins sometimes occur. Hepper & Wood 6021 (Yemen, Wadi Dur, Udaya, 22 Oct. 1975) determined by Holttum as C. dentata definitely has two pairs of anastomosing veins at most sinuses also dense small glands and some hooked hairs beneath. The microfiche of Forsskål’s type is not very clear but I think two pairs of anastomosing veins are sometimes present. There are undoubted true hybrids showing other characters such as slightly setose sporangia but at least some so-called hybrids could be mere forms of C. dentata. Detailed field studies and spore studies are needed; of the list of possible hybrids cited by Holttum (J. S. Afr. Bot. 40: 158 (1974)) he says “some of these have abortive spores”. Viane in B.S.B.B. 118: 49 (1985) has described a hybrid Thelypteris x varievenulosa from the Ivory Coast which he thinks is probably T. afra x T. hispidula (i.e. Pneumatopteris afra x Christella hispidula in Holttum’s nomenclature).