| Polemoniaceae | |
|---|---|
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| Polemonium caeruleum (type species) | |
Scientific classification | |
| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Angiosperms |
| Clade: | Eudicots |
| Clade: | Asterids |
| Order: | Ericales |
| Family: | Polemoniaceae Juss.[1] |
| Genera[2] | |
27; see text | |
ThePolemoniaceae (Jacob's-ladder orphlox family) are afamily offlowering plants consisting of about 27genera[2] with 270–400species ofannuals andperennials native to theNorthern Hemisphere andSouth America, with the center of diversity in westernNorth America.
Only one genus (Polemonium) is found inEurope, and two (Phlox andPolemonium) inAsia, where they are confined to cool temperate to arctic regions; both genera also occur more widely in North America, suggesting relatively recent colonization of the Old World from North America.
The family can be distinguished from most othereudicot families by theovary made up of three fusedcarpels (usually with three chambers, but with one chamber in some species).[3] The members of the family have fivesepals, fivepetals fused, and fivestamens that alternate with the lobes of thecorolla.
For decades, most sources used a classification of the family published by Grant in 1959, but new evidence, includingmolecular phylogeny, veins of the corolla, pollen, and theflavonoids present, have led to reclassifications, such as the 1998 classification by Grant.[3] It recognizes two subfamilies. The subfamily Cobaeoideae is tropical/subtropical and composed of six genera organized into five tribes. The subfamily Polemonioideae consists of 13 temperate genera. Grant divides it into three tribes, but with the disclaimer that it is not clear what the correct division is and that the genus classifications may be more useful in this subfamily.[3]
A number are widely grown asornamental plants, such asIpomopsis aggregata (skyrocket or scarlet gilia), and many species ofPhlox,Gilia andPolemonium. Thekantuta (Cantua buxifolia) is the national flower ofBolivia andPeru.
27 genera are accepted.[2]
One extinct genus,Gilisenium, has been placed in the family based on anEarly Eocene (Ypresian) fossil found in theGreen River Formation of Utah.[4]
Authority control databases: National |
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