''Clarkia williamsonii'' is a species of flowering plant

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

California California is a U.S. state, state in the Western United States, located along the West Coast of the United States, Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the List of states and territori ...

, where it is known from the forests and woodlands of the northern and central

Sierra Nevada foothills :''See Sierra Nevada for general information about the mountain range in the United States.'' The ecology of the Sierra Nevada, located in the U.S. states of California and Nevada, is diverse and complex: the plants and animals are a significant ...

Description

''Clarkia williamsonii'' is an erect annual herb with linear to lance-shaped leaves each a few centimeters long. The

inflorescence An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Morphologically, it is the modified part of the shoot of seed plants where flowers are formed o ...

produces opening flowers and buds which are closed except for the tips, where the

sepal A sepal () is a part of the flower of angiosperms (flowering plants). Usually green, sepals typically function as protection for the flower in bud, and often as support for the petals when in bloom., p. 106 The term ''sepalum'' was coined b ...

s do not fuse. The

s all separate or remain fused in pairs as the flower blooms. Each fan-shaped petal is up to 3 centimeters long and is usually lavender with a white area and a purple spot in the middle. The petals are occasionally solid deep red. A unique feature of this species is its tendency to have widespread

reciprocal translocation In genetics, chromosome translocation is a phenomenon that results in unusual rearrangement of chromosomes. This includes balanced and unbalanced translocation, with two main types: reciprocal-, and Robertsonian translocation. Reciprocal translo ...

s. Wedberg et al

showed that populations of this plant in the foothills of California had frequencies of translocation

heterozygosity Zygosity (the noun, zygote, is from the Greek "yoked," from "yoke") () is the degree to which both copies of a chromosome or gene have the same genetic sequence. In other words, it is the degree of similarity of the alleles in an organism. Mo ...

approaching 50%, while those in higher elevations in alpine regions have frequencies of less than 10%.

References

External links

Jepson Manual Profile — ''Clarkia williamsonii''''Clarkia williamsonii'' — U.C. Photo gallery
williamsonii Endemic flora of California Flora of the Sierra Nevada (United States) Plants described in 1857 {{Myrtales-stub