Harperocallis is congeneric with Isidrogalvia (Tofieldiaceae, Alismatales): Evidence from comparative floral morphologyстатья
Статья опубликована в высокорейтинговом журнале
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Дата последнего поиска статьи во внешних источниках: 18 июля 2013 г.
Аннотация: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.