Harperocallis is congeneric with Isidrogalvia (Tofieldiaceae, Alismatales): Evidence from comparative floral morphology

Abstract

Flowers of most Tofieldiaceae are inserted laterally in the axils of well-developed flower-subtending bracts in a racemose inflorescence, each flower possessing a characteristic calyculus. The monospecific genus Harperocallis, which is endemic to north-western Florida, represents the only member of Tofieldiaceae with a consistently solitary terminal flower. We compare flowers of H. flava with those of Isidrogalvia, a putative close relative of Harperocallis from South America. We analyse the resulting data in an extended morphological analysis for the entire family. Both Harperocallis and Isidrogalvia lack septal nectaries, which are functionally replaced by tuberculate glands on the ovary walls; in both genera the carpels are united with congenital carpel fusion at the gynoecium base. Flowers of both genera are relatively large and highly vascularized; the calycular phyllomes and tepals each possess several veins and the carpels contain (in addition to dorsal and ventral bundles) both lateral bundles and separate placental bundles that support massive intrusive placentae. The presence of a synascidiate zone with congenital intercarpellary fusion in both genera is correlated with the formation of heterocarpellary ventral bundles. Harperocallis is unusual in that the stamens are often supplied by three veins. Our morphological cladistic analysis supports earlier molecular data indicating a close relationship between Harperocallis and Isidrogalvia, and several morphological characters are revealed as synapomorphies of this sister-pairing. This finding, resulting from strong morphological similarities between Harperocallis and Isidrogalvia, allows the transfer of H. flava into Isidrogalvia.

Morphology ofMaundiasupports its isolated phylogenetic position in the early-divergent monocot order Alismatales

“…Although one‐traced stamens with a single unbranched vascular bundle are most common among angiosperms, taxa with multi‐bundled and even multi‐traced stamens are known from all major phylogenetic lineages, including monocots (e.g. Remizowa et al ., ), eudicots (e.g. Nuraliev, Sokoloff & Oskolski, ) and magnoliids (e.g.…”

Plastid phylogenomics and molecular evolution of Alismatales

“…We included new plastid genome data for 61 species, including 54 in Alismatales (specifically, full plastid gene sets representing the 79 protein-coding genes found in most angiosperms and four rDNA genes; Raubeson and Jansen, 2005). These taxa represent 49 of~54 genera in the core alismatids (Alismatales excluding Araceae and Tofieldiaceae, corresponding to Alismatidae sensu Les and Tippery, 2013), three of the four genera of Tofieldiaceae (Remizowa et al, 2011;Campbell and Dorr, 2013) and seven additional monocots (Table S1). The full taxon sampling for analysis included an additional 95 previously sequenced angiosperm genomes retrieved from GenBank and from matrices presented in Barrett et al (2013; including representatives of most major lineages of monocots, APG III, 2009) and Henriquez et al (2014; sampling focused on Araceae) (Table S1).…”

Floral vasculature and its variation for carpellary supply inAnthurium(Araceae, Alismatales)

“…This pattern of carpellary vasculature may vary with lateral or additional bundles described in many taxa, as basal angiosperms (e.g., Igersheim & Endress, 1998), some monocots as Acorales (e.g., Buzgo & Endress, 2000), Alismatales (e.g., Igersheim, Buzgo & Endress, 2000; Remizowa et al, 2011), Commelinales (e.g., Hardy & Stevenson, 2000; Hardy, Stevenson & Kiss, 2000), Poales (e.g., Remizowa et al, 2012; Reynders et al, 2012) and Zingiberales (e.g., Box & Rudall, 2006), and also amongst eudicots (e.g., Litt & Stevenson, 2003; Nuraliev, Sokoloff & Oskolski, 2011). …”