Polemonium

Polemonium boreale in Spitsbergen

Called Jacob's Ladders ( Polemonium ), also Jacob's ladder or locking herb, a genus of the family of locking herb plants is ( Polemoniaceae ), which comprises about 20 to 30 species. She is the namesake genus of the family Polemoniaceae, and the subfamily of Polemonioideae.

Description

Jacob ladders are usually perennial, rarely annual, herbaceous plants. Perennial species grow from rhizomes. The sprossbürtigen Leaves are compound, alternate and pinnate. The hairs may be glandular or nichtdrüsig.

The most terminal inflorescences are panicles or heads. The cup and the crown are radial symmetry, all the sepals are of the same size and shape, the crown is laid out flat, wheel-shaped or funnel-shaped.

The stamens are all set at the same height in the lower part of the corolla tube, the hairy stamens are of equal length. The anthers are just like the stylus included to standing out, the pantoaperturat pollen with 30 to 100 apertures.

The fruit capsules open along the compartments, each compartment they contain from one to twelve ovate to elliptic seeds. The chromosome number is 2n = 18

Dissemination

The genus is found in North America and Eurasia in forests, scrublands and temperate - humid locations.

System

The genus comprises about 20 to 30 species, including:

  • Polemonium antarcticum Griseb.
  • Polemonium boreale Adams; it comes in the far north of Europe (Norway, Svalbard, Jan Mayen ), North America (Alaska, Canada, Greenland) and Asia ( Siberia to Kamchatka ) before
  • Polemonium brandegeei ( A. Gray ) Greene
  • Polemonium caeruleum L.; it is found in Europe, Asia and North America; with several subspecies, including: Polemonium caeruleum subsp. caeruleum
  • Polemonium caeruleum subsp. himalayanum ( Baker) H. Hara
  • Polemonium caeruleum subsp. villosum ( Rudolph ex Georgi ) Brand (. syn: Polemonium acutiflorum Willd ex Roem & Schult; Polemonium racemosum Kitam. .. )
  • Polemonium caeruleum subsp. yezoense ( Miyabe & Kudo ) H. Hara ( Syn: Polemonium yezoense ( Miyabe & Kudo ) Kitam. )
Asterids Agricultural Research Service
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