Floral morphology, anatomy and development are examined in Xyris grandis (Xyridaceae: Poales), with an emphasis on petal and sepal organogenesis and vasculature. Xyris is one of relatively few monocots in which the perianth is differentiated into two distinct whorls (here termed a double perianth). Xyris also possesses highly unusual perianth vasculature, with each petal being supplied by three veins and each sepal by a single vein, compared with the opposite condition in most other angiosperms with a double perianth. However, perianth development in X. grandis shows a pattern that is typical for monocots, with petals not markedly delayed in development. Xyris grandis is also remarkable for its petal aestivation, with each petal surrounding a stamen and two branches of adjacent staminodes, a type that is not reported for other Xyridaceae and may contribute to secondary pollen presentation. The results are discussed in the context of the diversity of a double perianth in monocots, compared with eudicots. Based on current data, our preferred hypothesis is that meristic differences are at least partly responsible for the apparently widespread occurrence of three‐traced petals in monocots. © 2012 The Linnean Society of London, Botanical Journal of the Linnean Society, 2012, 170, 93–111.

The genus Aspidistra (Asparagaceae) shows strong variation of flower groundplan. We add further evidence of this variation describing a new species, Aspidistra paucitepala from southern Vietnam that has flowers with 2-4 tepals, 2-4 stamens and a gynoecium with unilocular ovary. Bisexual flowers with three tepals and three stamens are extremely rare among monocots with biotic pollination. Compared with typical trimerous pentacyclic monocot flowers, they can be either interpreted as trimerous and tricyclic or as 1.5-merous (at least in perianth and androecium) and pentacyclic. Both interpretations imply floral features unusual for ‘higher’ Asparagales. Aspidistra paucitepala resembles recently described A. brachystyla from northern Vietnam in narrow funnel-shaped to nearly tubular perianth with very small lobes and short cylindrical pistil with stigma located below the level of anthers. As species of the taxonomically diverse genus Aspidistra are frequently observed in the field without reproductive structures and cannot be properly identified, a need for DNA barcoding approach is obvious. We present preliminary data showing that plastid psbA-trnH and nuclear 5S-NTS regions could be useful for DNA barcoding of Aspidistra.

No abstract

More than one kind of myiophily is present in Aspidistra. Brood site pollination was documented for the first time in Aspidistra. The pollination system of A. xuansonensis differs from other kinds of brood site pollination in the exit of the larvae prior to the decomposition of floral parts.

No abstract

The genus Aspidistra is the most diverse in southern China and northern Vietnam. We describe a new species Aspidistra xuansonensis from northern Vietnam including two varieties: A. xuansonensis var. xuansonensis with greenish white perianth and A. xuansonensis var. violiflora with purple perianth. We present DNA barcoding data of plastid psbA-trnH and nuclear 5SNTS regions for these two varieties in comparison with three other species of Aspidistra. Morphology of monopodial shoots of A. xuansonensis is described in detail. A. xuansonensis resembles recently described A. lingyunensis but differs in longer leaf petioles, longer lamina, perianth tube shape (tubular, widened at the base vs. funnel-shaped), higher anther position, and pistil shape (suddenly obconic to nearly umbrella-shaped vs. obconic gradually widened to stigma).

Biermannia King & Pantling (1898a: 591) comprises about ten species distributed from northeastern India and southern China through the Indochinese and Malay Peninsulas to Sumatra, Java and Borneo (Comber 1990, 2001, Seidenfaden & Wood 1992, Pearce & Cribb 2002, Chen & Wood 2009, Chase et al. 2015). All species of this genus are miniature, canopy epiphytes with small, unattractive fugacious flowers lasting only few hours in the morning. As a result, representatives of this genus are easily overlooked in botanical surveys, poorly represented in herbaria and remain infrequently inventoried in local floras throughout its range. One more new species that differs strikingly from all hitherto known species of this genus was recently discovered in southern Vietnam. Here we describe and illustrate this unusual plant.

No abstract