Pleuridium julaceum Is Conspecific with Astomiopsis sinensis

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The presence of an emersed capsule, an annulus, a central strand, and perichaetial leaf costal transverse sections showing a row of large, oval, ventral cells with thin upper walls and thickened lower walls, a central stereid band, and a dorsal cell layer consisting of small, ovate, thick-walled cells aligns Pleuridium julaceum Besch. with Astomiopsis sinensis Broth. The new combination, Astomiopsis julacea (Besch.) Yip & Snider, is made. Astomiopsis julacea is known from Yunnan and Sichuan Provinces, China, and Tokyo, Japan. The generic placement of Pleuridium julaceum Besch. has been questionable since its inception. Described by Bescherelle (1898), P. julaceum was based on a collection (Matsumura no. 71) from Tokyo, Japan. In the original publication, Bescherelle (1898) provided only a general description of the sporophyte features of P. julaceum. Noguchi (1987), however, stated that the taxonomic status of P. julaceum ...is not certain as the sporophyte is unknown. Matsui and Iwatsuki (1990) recently reported observing a single, flattened, cleistocarpous capsule in a purported isotype (Matsumura? NICH) collected from the Koishikawa Botanical Garden, but they did not provide detailed observations on capsule structure. We have studied the type collection (BM) and several isotypes (Matsumura no. 71, H-Br, s) of P. julaceum. The specimens from BM and s contain only gametophyte plants; however, an isotype from H-Br contains a single plant with an immature, emersed capsule among the numerous gametophytes. (Emersed was a term used by Brotherus (1929) and later by Snider (1987) to describe the character state when the base of the urn is parallel with the tips of the perichaetial leaves; the term is appropriate when the capsule is neither immersed, emergent, nor fully exserted). Unfortunately, we were unable to study the specimen cited by Matsui and Iwatsuki (1990), as that collection could not be located in the NICH herbarium (M. Mizutani, pers. comm.). Although the label information on many of the packets of Pleuridium julaceum is incomplete, all of the specimens we have examined appear to have been collected in by J. Matsumura. A specimen from TNS is labeled JAPAN: Botanical Garden, Tokyo, Matsumara no. 71. The original label (in Japanese) inside the packet is stamped co-TYPUS and Jinzo as the collector, and botanical garden, Tokyo as the location; however, it does not give a collection number. Matsui and Iwatsuki (1990) recorded a collection ? s.n. labeled from the Koishikawa Botanical Garden. Although speculative at this point, it may well be that all of these collections were made from the same location in the Koishikawa Botanical Garden, where Matsumura apparently had been associated since 1877 (Stafleu & Cowan 1981). In addition, we have examined two collections from Sichuan Province, China, labeled Tristichium sinensis (herbarium no. 01810 IBSC) and Pleuridium chinensis (a nomen nudum) (Chen 043052 PE). The characters of these two specimens match those of the Matsumura specimens. One difficulty in correctly placing Pleuridiumjulaceum concerns the lack of good sporophyte material available for observation. We were fortunate to examine two additional, apparently non-type, collections of P. julaceum (H-Br), collected from by Matsumura. The specimens were labeled as numbers 135 and 167, but it is unclear as to whether these represent collection numbers assigned by Matsumura. Both collections contain plants with abundant sporophytes, and one (135) included many with well-developed emersed capsules. Close examination of the emersed capsules reveals 2-3 tiers of vesiculose cells which form an annulus in the upper capsule region. Additionally, transverse sections of the costa near the base of the perichaetial leaves show a single row of ventral guide cells; two rows of stereids surrounding a group of two-layered, thin-walled accessory (begleiter) cells; and a dorsal layer of undifferentiated cells. At mid-leaf, the costa contains a row of large, oval, ventral cells with thin upper walls and thickened lower walls, a central stereid band, and a dors l cell layer consisting of small, ovate, thickwalled cells. A small central strand is present in the stem transverse section. We observed identical gametophyte features in the sterile type and isotype collections. These characteristics, combined with 0007-2745/98/86-88$0.45/0 This content downloaded from 207.46.13.128 on Tue, 06 Sep 2016 05:18:32 UTC All use subject to http://about.jstor.org/terms 1998] YIP & SNIDER: PLEURIDIUM AND ASTOMIOPSIS 87 emersed capsules, oblong-ovate perichaetial leaves, and long excurrent costae, are identical to those described by Brotherus (1929) for Astomiopsis sinensis Broth. The name Pleuridium julaceum (1898) predates Astomiopsis sinensis (1929), consequently a new combination is required. ASTOMIOPSIS JULACEA (Besch.) Yip & Snider,