A third species of Villarsia from South Africa, V. manningiana sp. nov., differs from V. capensis and from V. goldblattiana in one or more of these characters: size of leaves and inflorescences, length of pedicels, number of flowers per inflorescence, number of ovules per ovary. and surface of seeds. As now circumscribed. V. capensis consists of an eastern and a western suite of local populations within the Western Cape Province.

O rnduff Robert, Department of Integrative Biology, University of California, Berkeley, California 94720-3140 USA) 1996. The breeding system of Villarsia exaltata (Menyanthaceae), a distylous species. Telopea 6(4): 805-811. Ten of the 15 species of the predominantly Australian genus Villarsia have distylous flowers. Eight of these are diploid or predominantly so. In six species the incompatibility relationships within and between the two morphs resemble the expected type, but the distylous breeding systems of four species deviate from that conventionally associated with distyly. This paper reports on the breeding system of the widespread eastern Australian Villarsia exaltata, which has distylous flowers, striking dimorphisms in style length and stigma morphology of the two floral types, high pollen stainability, but not consistent intermorph size differences in the pollen grains. Unlike the other distylous Australian species, V. exaltata is hexaploid. Intermorph pollinations of pin plants (those with long-styled flowers) produced 5.6 times more seeds than intramorph pollinations; intermorph pollinations of thrum plants (those with short-styled flowers) produced 33.4 times more seeds than intramorph pollinations. Thus an incompatibility system is associated with distyly in this species; the system appears to be stronger in thrum plants than in pin plants. Pollinations utilizing different pairs of parent plants often differed in mean seed-sets following a given class of pollination. Some intramorph pollinations produced unexpectedly high seed-sets that were equal or nearly equal to those produced by intermorph pollinations of the same seed parent. The breeding system of V. exaltata is not considered to represent a condition ancestral to the derivative breeding systems associated with distyly elsewhere in the genus, but it demonstrates the kind of intrapopulation variability that is necessary before natural selection can lead to the development of these derivative systems. Little is known of the population biology or the functioning of distyly in natural populations of V. exaltata, features that would reward study by botanists resident within the range of this species.

The restricted perennial diploid herb, Villarsia lasiosperma, of southwestern Western Australia has distylous flowers with dimorphism in style and stamen length, stigma morphology, and pollen size. In order to assess the presence and nature of an incompatibility system in this species, a crossing program was carried out using 17 plants grown from seeds collected in two field populations. Pollen stainabilities of these plants mostly exceeded 95%. Mean seed-set of Longs following intermorph pollinations was c. 24 seeds per pollination and for Shorts was c. 16 seeds per pollination. Approximately three-quarters of the Longs and Shorts produced no seeds after self-pollination; the remainder produced very few seeds following such pollinations. No Shorts produced seeds after intramorph cross-pollinations. However, about half the Longs exhibited various levels of weakened intramorph incompatibility, with mean seed-sets following intramorph cross-pollinations up to half the mean seed-sets following intermorph pollinations. In the behavior of Longs, the incompatibility system of V. lasiosperma differs from the idealized distylous breeding system, but resembles that of a purported close relative, V. exaltata of eastern and southeastern Australia.

Scanning electron microscopic investigations of seed morphology of the five genera of Menyanthaceae illustrate a remarkable diversity of seed characteristics for a small family. Seeds of the monotypic northern hemisphere Menyanthes and Fauria are unomamented and similar, and those of the monotypic Liparophyllum of New Zealand and Tasmania are similar to some Australian species of Villarsia . Seed characteristics within the larger genera Villarsia and Nymphoides are variable and mostly species specific, but do not lend support to taxonomic separation of these genera. Interspecific affinities postulated on other grounds are, in many instances, supported by seed morphology. Various seed-coat features are believed to aid in water or animal dispersal of the seeds of several species. Ant dispersal appears to be important for Villarsia and Nymphoides in Australia, but does not seem to occur in these genera or in other members of the family outside of Australia.

Using trunk heights as a predictor of the ability to produce reproductive structures, the single population of Cycas armstrongii Miq. sampled for this trait appeared to contain a substantial number of "mature" but non-reproductive individuals for the two pollination episodes evident during the period of study. While no estimate of this number was attempted, these observations are consistent with those on other cycads where mature plants may "rest" between successive reproductive episodes. There is no evidence of a difference in size of reproductive females compared with males. The small weevil Ulomoides xamiaphila (Cart.) and an as yet undescribed genus of the subfamily Cossoninae (Curculionidae) were collected from male cones. Their role in the pollination of this cycad, if any, is unclear. Although C. armstrongii has been termed deciduous, leaf fall appears to be irregular within a population and to be accelerated in relatively short plants by fire damage. Leaf fall and production of new leaves after natural or fire-induced defoliation are not synchronized among individuals within a population.

Villarsia marchantii, known from a single population growing in a shaded woodland of the Porongurup Range in southwestern Western Australia, is newly described. It is closely related to V. calthifolia, another endemic of this group of mountains, which occurs in exposed situations at or above timberline. In addition to differences in habitat, vegetative, floral, and fruit characters, seed size, flowering time, duration of seed maturation, and susceptibility to Septoria infection, V. marchantii has strongly distylous flowers and is self-incompatible, whereas V. calthifolia has weakly distylous flowers, is fully self-compatible, and shows some degree of autogamy. Artificial interspe- cific hybrids exhibited reduced pollen stainabilities. Villarsia Vent. is a genus of ca. 16 species oc- curring in southeastern Asia, Australia, and South Africa (Aston 1969). Nine species occur in southwestern Western Australia, where the genus exhibits its greatest degree of morpho- logical and ecological diversity (Ornduff and Chuang 1988). In 1983 I spent several months in Western Australia studying features of the breeding systems of Villarsia, most of which are distylous (Ornduff 1986). In the course of mak- ing field observations and collections, I sampled populations of V. calthifolia F. Muell., an en- demic of the small (3 x 12 km) granitic Poron- gurup Range. Subsequent study of cultivated plants attributed to this species and of material obtained on a second visit to the range late in 1988 indicates that there are two closely related species of Villarsia occurring there that differ in

Chromosome numbers are reported for eight of the nine Western AustralianVillarsia species.Villarsia albiflora, V. calthifolia, V. capitata, V. congestiflora, V. lasiosperma, V. latifolia, andV. violifolia are diploid with n=9. Five populations ofV. parnassiifolia are diploid and three are tetraploid (n=18). The morphological, ecological, and breeding-system diversity of the Western Australian species is largely not associated with the tetraploidy or hexaploidy that characterizes otherVillarsia species in eastern Australia and South Africa. The majority of Western AustralianVillarsia species are restricted to the high rainfall zone of southwestern Western Australia, where favorable climatic and edaphic conditions may have existed since mid-late Tertiary times.