The genus

Genus

In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 Comandra contains a single species

Species

In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...

, C. umbellata, with 4 sub-species distributed in North America

North America

North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...

 and the Mediterranean. C. umbellata is considered to be semi-parasitic

Parasitic plant

A parasitic plant is one that derives some or all of its sustenance from another plant. About 4,100 species in approximately 19 families of flowering plants are known. Parasitic plants have a modified root, the haustorium, that penetrates the host plant and connects to the xylem, phloem, or...

.

Description

Comandra is a small herb that lives as a parasite on plant root

Root

In vascular plants, the root is the organ of a plant that typically lies below the surface of the soil. This is not always the case, however, since a root can also be aerial or aerating . Furthermore, a stem normally occurring below ground is not exceptional either...

s and has tiny white flower

Flower

A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants . The biological function of a flower is to effect reproduction, usually by providing a mechanism for the union of sperm with eggs...

s.

Parasitism

Comandra is not an obligate parasite

Parasitic plant

A parasitic plant is one that derives some or all of its sustenance from another plant. About 4,100 species in approximately 19 families of flowering plants are known. Parasitic plants have a modified root, the haustorium, that penetrates the host plant and connects to the xylem, phloem, or...

 since it obtains nutrition through photosynthesis

Photosynthesis

Photosynthesis is a chemical process that converts carbon dioxide into organic compounds, especially sugars, using the energy from sunlight. Photosynthesis occurs in plants, algae, and many species of bacteria, but not in archaea. Photosynthetic organisms are called photoautotrophs, since they can...

, however it does have a wide host range, including, but not limited to many herbs including Aster, Antennaria

Antennaria

Antennaria is a genus of about 45 species of herbaceous perennial plants in the family Asteraceae, native to temperate regions of the Northern Hemisphere, with one species in temperate southern South America; the highest species diversity is in North America...

, Solidago, several shrub species Rosa

Rose

A rose is a woody perennial of the genus Rosa, within the family Rosaceae. There are over 100 species. They form a group of erect shrubs, and climbing or trailing plants, with stems that are often armed with sharp prickles. Flowers are large and showy, in colours ranging from white through yellows...

, Rubus

Rubus

Rubus is a large genus of flowering plants in the rose family, Rosaceae, subfamily Rosoideae. Raspberries, blackberries, and dewberries are common, widely distributed members of the genus. Most of these plants have woody stems with prickles like roses; spines, bristles, and gland-tipped hairs are...

, Fragaria, Vaccinium

Vaccinium

Vaccinium is a genus of shrubs or dwarf shrubs in the plant Family Ericaceae. The fruit of many species are eaten by humans and some are of commercial importance, including the cranberry, blueberry, bilberry or whortleberry, lingonberry or cowberry, and huckleberry...

, and several tree species Acer, Betula, Populus, as well as Carex

Carex

Carex is a genus of plants in the family Cyperaceae, commonly known as sedges. Other members of the Cyperaceae family are also called sedges, however those of genus Carex may be called "true" sedges, and it is the most species-rich genus in the family. The study of Carex is known as...

, and various grasses.

Pathogens

Comandra umbellata is the alternate host for the rust fungus

Rust (fungus)

Rusts are plant diseases caused by pathogenic fungi of the order Pucciniales. About 7800 species are known. Rusts can affect a variety of plants; leaves, stems, fruits and seeds. Rust is most commonly seen as coloured powder, composed off tiny aeciospores which land on vegetation producing...

 Cronartium comandrae

Cronartium

Cronartium is a genus of rust fungi in the family Cronartiaceae.They are heteroecious rusts with two alternating hosts, typically a pine and a flowering plant, and up to five spore stages...

Peck., or comandra blister rust, that affects pine

Pine

Pines are trees in the genus Pinus ,in the family Pinaceae. They make up the monotypic subfamily Pinoideae. There are about 115 species of pine, although different authorities accept between 105 and 125 species.-Etymology:...

 species in North America. Comandra blister rust can cause losses to volume of up to 7% in some regions where it is common.

When Comandra umbellata is infected by Cronartium comandrae basidiospore

Basidiospore

A basidiospore is a reproductive spore produced by Basidiomycete fungi. Basidiospores typically each contain one haploid nucleus that is the product of meiosis, and they are produced by specialized fungal cells called basidia. In grills under a cap of one common species in the phylum of...

s, yellow blister-like spots bearing urediniospore

Urediniospore

Urediniospores are the thinner-walled spores of some fungi: , from which the basidium arises.-Morphology:*Urediniospores are usually consist of two dikaryote nuclei within one constricted cell resembling the number 8 without a septation...

s appear on the leaves of the plant within 20 days. In the following weeks teliospores develop as brown hairlike structures that germinate to produce basidiospores, the Cronartium comandrae life-stage capable of infecting pines.

External links

• http://calphotos.berkeley.edu/cgi/img_query?where-genre=Plant&rel-namesoup=like&where-namesoup=Comandra