Cladistic Analysis of Sphagnum in Northeast China

He Xiao-Lan, Aur Chih-Wen

Received:1900-01-01 Revised:1900-01-01 Online:1991-03-10 Published:1991-03-10
Contact: He Xiao-Lan

Abstract:

This paper deals with the phylogenetic relationships in Sphagnum using the

Wagner Groundplan-Divergence method. The main principle of the Wagner GPD method

is grouping based on synapomorphy derived from outgroup comparison and ontogenetic

analysis whenever possible. We make use of 21 available characters from gametophytes, es-

timate plesiomorphic conditions on the principle that characters found in the group under

study and in most or all members of related groups are plesiomorphic, while those found only

within the group are apomorphic, and finally arrange taxa according to shared derived fea-

tures. In the Wagner tree diagrams, all characters can be placed on a Wagner tree so that the

various relationships in the genus Sphagnum can be visualized. The results were as follows:

1. The genus Sphagnum can be divided into six sections, i.e. Sphagnum, Squarrosa,

Acutifolia, Cuspidata, Subsecunda and Polyclada. They are almost consistent withe those de-

rived from classical and numerical taxonomy of Sphagnum.

2. In Wagner tree diagrams, Section Sphagnum and Sect. Squarros were branched earli-

er, so they are primitive and the other four sections were last branched, so they are

derived. Sphagnum magellanicum is a rather primitive species, whereus S. girgensohnii and

S. fimbriatum are rather advanced ones in the 14 species of Sphagnum investigated.

Key words: Sphagnum, plesiomorphy, apomorphy, phylogenesis, Wagner GPD method

He Xiao-Lan, Aur Chih-Wen. Cladistic Analysis of Sphagnum in Northeast China[J]. .

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