Tectaria griffithii (Baker) C. Christensen (1934: 180)

Ding, Hui-Hui, Chao, Yi-Shan & Dong, Shi-Yong, 2013, Taxonomic novelties in the fern genus Tectaria (Tectariaceae), Phytotaxa 122 (1), pp. 61-64 : 61-62

Tectaria griffithii (Baker) C. Christensen (1934: 180) .

Basionym :— Nephrodium griffithii Baker in Hooker & Baker (1867: 300). Type :— MYANMAR. Without locality, without date, Griffith s.n. (holotype K!) .

= Nephrodium yunnanense Baker (1906: 11) ; Tectaria yunnanensis (Baker) Ching (1931: 24) , syn. nov. Type:— CHINA. Yunnan: Mengtze, Red river mountains, without date, Hancock 193 (holotype K!).

Note:— Tectaria griffithii has long been confused with T. multicaudata ( Clarke 1880: 540) Ching (1931: 20) . Both Ching (1931) and Holttum (1991a, b) considered the two species as conspecific, albeit Ching (1931) took T. multicaudata as the accepted name while Holttum (1991a, b) adopted T. griffithii . In fact, T. griffithii and T. multicaudata are distinct in the venation pattern. The holotype of T. griffithii (Griffith s.n., K) is characterized by having fully anastomosing veins, vein areoles mostly with free veinlets included, and lacking costal or costular areoles ( Fig. 1a ). The holotype of T. multicaudata (Clarke 18427, K) has partly anastomosing veins that form narrow areoles immediately beside costae or costules, without included free veinlets (or rarely occurring) in areoles ( Fig. 1b ). Noticeably, the feature of venation was clearly stated in the protologues of T. griffithii and T. multicaudata . Baker described the venation of T. griffithii as having “main veins distinct to the edge, with copious free included veinlets” ( Hooker & Baker 1867: 300). For the venation of T. multicaudata, Clarke stated that “I can see little difference in the venation and sori between this and Nephrodium cicutarium var. coadunata ” ( Clarke 1880: 540). As we know, N. cicutarium var. coadunata mentioned by Clarke is nowadays T. coadunata ( Smith 1842: 184) C. Christensen (1931: 331) , which is characterized by veins forming costal and costular areoles lacking free included veinlets ( Holttum 1991a). Unfortunately, later authors ignored the easily recognizable difference of venation between the two species. It is notable that the venation in such two conditions (costal areoles present or not) is the sole difference between two sections of Tectaria proposed by Holttum (1988, 1991a). According to Holttum’s subdivision of Tectaria , T. multicaudata should be grouped into sect. Sagenia, whereas T. griffithii to sect. Tectaria .

Tectaria yunnanensis is included here in T. griffithii . When comparing the holotypes of both species, we found that they are similar in nearly all important characters, such as coarsely dissected fronds, fully anastomosing veins without costal or costular areoles, large sori in two rows between main veins, and sori rather deeply impressed on abaxial surface of lamina. They doubtless represent a single species. It is also noticed that there are no scales above the base of stipes in this species. Scaly stipes, previously considered a diagnostic character of T. griffithii (e.g., Holttum 1988, Tagawa & Iwatsuki 1988, Wang 1999), is actually a characteristic feature of T. multicaudata .

Figures

FIGURE 1. Comparison of the venation between Tectaria griffithii (Baker) C.Chr. (a) and T. multicaudata (C.B.Clarke) Ching (b). a) Portion of a pinnule on basal pinna, based on the holotype of T. griffithii (Griffith s.n., K); b) portion of a pinnule on basal pinna, based on the holotype of T. multicaudata (Clarke 18427, K).