Conostylis

Abstract: Abstract The genus Conostylis (Haemodoraceae) is endemic to fire-prone south-western Australia. To gain an understanding of the effect of some fire-related germination cues, eight Conostylis taxa were tested in response to water, nitrate, smoke water and karrikinolide (KAR1) under light and dark conditions, when seeds were freshly collected and after a year of burial. The germination of all taxa tested was higher in response to smoke water and KAR1 than in water alone, whereas nitrate did not stimulate germination. Germination was higher in all taxa following 1 year of burial than in fresh seeds. Recently, glyceronitrile has been identified as another chemical in smoke water, apart from KAR1, that can stimulate the germination of certain species. The relative response of eight Conostylis taxa to KAR1, glyceronitrile and smoke water was examined in laboratory-stored seeds. Germination of these taxa was promoted by both smoke water and KAR1, except for C. neocymosa, which had high germination regardless of treatment. Four of the other seven taxa germinated to higher levels in at least one of the glyceronitrile concentrations tested (10, 50 or 100 μM) than in water alone. However, in only two of these taxa, C. aculeata subsp. septentrionora and C. juncea, was germination in glyceronitrile as high as that in smoke water. Thus, the response to glyceronitrile is not uniform across Conostylis taxa. Generally, germination was higher with KAR1 than glyceronitrile, suggesting that although some Conostylis taxa have the capacity to respond to glyceronitrile, KAR1 is the more important germination stimulant for this genus.

Abstract: We sequenced the plastid gene matK and the nuclear ribosomal spacer ITS for 39 of the 47+ species of Conostylis as well as its monotypic sister genus Blancoa, which some authors have included within Conostylis. Conostylis received 99% bootstrap support as monophyletic, with 100% support that Blancoa is its sister. Within Conostylis, the study provides strong support for two large sister clades, which we refer to as clades A (100%) and B (99%). Clade A consists of C. subgen. Conostylis plus the recently discovered C. glabra of C. subgen. Pendula sect. Divaricata (100%), and C. subgen. Pendula sect. Appendicula (100%). Clade B consists of species mostly placed within the remainder of C. subgen. Pendula but also contains members of the other small subgenera. Subgenus Pendula can be recircumscribed as monophyletic by excluding sect. Appendicula, Conostylis phathyrantha, and C. glabra and including subgen. Androstemma and subgen. Greenia. The status of the other two minor subgenera-C. subgen. Brachycaulon and C. subgen. Bicolorata-requires further investigation. Conostylis sect. Divaricata is polyphyletic. Ancient vicariance events are postulated for Conostylis involving separation of major clades in the northern and southern kwongan regions of southwestern Australia. The phylogenetic pattern in Conostylis is consistent across several lineages with the prolonged persistence of relictual taxa combined with explosive more recent speciation, the latter pronounced in the northern kwongan. There is evidence of significant divergence in major speciation mechanisms and chromosome number change among the three most species-rich subgenera/sections (dysploidy in Pendula and Appendicula vs. diploid speciation in Conostylis). Further investigation is needed to evaluate these ideas and elucidate the patterns of speciation in this most diverse genus of Haemodoraceae.

Abstract: Chromosome numbers of n 15 are reported for Barberetta aurea, Wachendorfia paniculata, and W. thyrsiflora; n = ca. 19-21 for Dilatris pillansii; n = 24 for Lachnanthes caroliniana; n = 21 for Lophiola aurea; and n = 36 for Lanaria plumosa, a genus of uncertain familial position sometimes assigned to Haemodoraceae. Barberetta and Wachendorfia are believed to be closely related, but the relationships of the other genera are unclear and indicate that further detailed study is merited. The family Haemodoraceae has been variously circumscribed by different authors. A recent detailed study of familial limits recognized 14 genera ( Geerinck, 1969; but see de Vos, 1956, and Hutchinson, 1973). The tribe Conostylideae contains the Australian genera Anigozanthos, Conostylis, and Tribonanthes. The tribe Haemodoreae contains the Australasian-Oceanic genera Haemodorum and Phlebocarya; the New World genera Lophiola, Lachnanthes, Schiekia, Pyrrorhiza, Hagenbackia, and Xiphidium; and the South African Barberetta, Dilatris, and Wachendorfia. The New World genera are monotypic; only Barberetta of the Old World genera is monotypic, with the others containing a few to many species. In South Africa, Wachendorfia is particularly variable and is in need of systematic study. Although chromosome counts are available for several species of the Conostylideae (Green, 1960), only a single chromosome count has been published for the considerably larger and more widespread Haemodoreae. This paper presents chromosome counts of two New World and three South African genera of Haemodoraceae. Because Lanaria has on occasion been referred to the Haemodoraceae, a chromosome count for it is also included here.