Eleven species of theScilla sibericaalliance, a well defined monophyletic group within the “genus by tradition”Scilla, have been investigated embryologically with special reference to embryo sac and endosperm development. Data are now available for 15 out of 20 known species. In most species embryo sacs develop according to the bisporic Allium‐type, only inScilla roseniiaccording to the tetrasporic Drusa‐type. Endosperm development is either nuclear or helobial (in 10 and 4 species respectively, unknown in 1). The taxonomic significance of these traits is evaluated after character polarisation by out‐group comparison. Among the out‐group taxa,S. persicamay be considered as the sister group of theS. sibericaalliance because only these two groups have an Allium‐type embryo sac, a synapomorphy derived from the plesiomorphic Polygonurn‐type. The Drusa‐type in S.roseniiis an autapomorphy for that species and evolved from an Allium‐type embryo sac.S. roseniiis distinct from its sister speciesS. koenigii, previously thought to be conspecific. Nuclear endosperm is considered to be plesiomorphic rather than apomorphic within theS. sibericaalliance, with respect to its occurrence in the presumed sister group and other outgroup taxa (S.hohenackerigroup,S. bifoliaalliance), but some doubt remains because of a helobial endosperm occurring in the out‐group taxonS. messeniaca. The distribution of other synapomorphies within theS. sibericaalliance suggests that a helobial endosperm evolved as a synapomorphy forS. bithynica, S. melainaandS. mischtschenkoana, but as a parallel trait inS. leepii. Species status for
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