Crossosomataceae

Crossosomataceae
Crossosoma bigelovii
Systematics
Eudicotyledons Nuclear eudicotyledons Rosids Eurosiden II Order : Crossosomatales Family : Crossosomataceae
Scientific name
Crossosomataceae
Engler

The Crossosomataceae are a family of plants and give their name to the order Crossosomatales . It consists of four genera and is restricted to the southwest of North America .

description

Crossosoma californicum , illustration

The Crossosomataceae are deciduous, heavily branched shrubs . The leaf position is spiral or opposite. The leaves are rather small (less than five centimeters), the stipules likewise or absent.

The xylem vessels have simple perforations.

The flowers arise individually in the leaf axils. In the flowers , calyx and crown are different and usually hermaphroditic. There is also a hypanthium , but no nectaries . The flowers are (three) four to five (six) numbered. The petals are white, nailed, spatulate or round. There are four to many stamens that face the calyx. The tapetum cells are polyploid. The pollen is aperturat (with two to three apertures) and colporat, as well as two-celled. The ovary consists of one to five (nine) carpels. The (one) two to many ovules per carpel are amphitropic or campylotropic. The Archespor is multicellular. The styluses are short.

The follicle is leathery and opens on both sides. The seeds are brown to black and have a fringed aril and a thin to thick, oily endosperm . The embryo is well differentiated. Germination takes place epigeously.

The basic chromosome number is x = 6. Inulin and ellagic acid are known ingredients . Yellow, needle-shaped crystals of calcium oxalate often appear in the leaf mesophyll .

distribution

The family is only found in the temperate to subtropical areas of the Neotropics. It occurs in arid areas in the western and southwestern United States and in Mexico.

Crossosoma californicum

Glossopetalon spinescens

Glossopetalon spinescens var. Aridum

Systematics

The family was first described by Adolf Engler in 1897 (Die Natural Plant Families Nachtr. 1: 185. 1897). In the past, the family was placed in the order of the rose-like (Rosales) or viewed as a sister group of the Geraniaceae . Today they are placed in the relatively new order Crossosomatales . The Crossosomataceae are the sister group of the Stachyuraceae . Both have the following features in common: No crystals / drusen in the flowers; X-shaped anthers; sclerotic testa. The two groups separated around 68 ± 10 million years ago. A 2003 study confirmed the family's monophyly.

There are four types:

• Apacheria C.T. Mason : With only one species:
  • Apacheria chiricahuensis C.T. Mason : It occurs in Arizona and New Mexico at altitudes between 1700 and 2100 meters.
• Crossosoma Nutt. : With two types:
  • Crossosoma bigelovii S. Watson : It occurs in Arizona, California, Nevada and in the Mexican states of Baja California , Chihuahua and Sonora .
  • Crossosoma californicum Nuttall : It occurs in California and Baja California, Mexico.
• Glossopetalon A.Gray (including Forsellesia Greene ): With about 4 species:
  • Glossopetalon clokeyi (Ensign) H. St. John (Syn .: Forsellesia clokeyi Ensign ): It occurs in Nevada at altitudes between 2100 and 3000 meters.
  • Glossopetalon pungens Brandegee (Syn .: Forsellesia pungens (Brandegee) A. Heller ): It occurs in Nevada and California.
  • Glossopetalon spinescens A. Gray (Syn .: Forsellesia spinescens (A. Gray ) Greene): It occurs in six varieties in the western United States and Mexico.
  • Glossopetalon texense (Ensign) H. St. John (Syn .: Forsellesia texensis Ensign ): It occurs in Texas.
• Velascoa Calderón & Rzed. : With only one type:
  • Velascoa recondita Calderón & Rzed. : It occurs in the northeastern Mexican state of Querétaro .

Sources and further information

• The family at DELTA by L. Watson & MJ Dallwitz. (Section description)
• The family at the The family at the AP website. (Section description)

Individual evidence

1. ↑ Victoria Sosa, Mark W. Chase: Phylogenetics of Crossosomataceae based on rbcL Sequence Data. In: Systematic Botany. Vol. 28, 2003, ISSN  0363-6445 , pp. 96-105, online .
2. ↑ ^{a b c d e f g h i j} Charles T. Mason Jr. †, George Yatskievych: Crossosomataceae Engler. In: Flora of North America, vol. 9. [1] .
3. ↑ First description 1997 (PDF; 553 kB)  ( page no longer available , search in web archives )  Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice.  

Web links

Commons : Crossosomataceae  - collection of images, videos and audio files

• Crossosomataceae at Tropicos.org. Missouri Botanical Garden, St. Louis
• Crossosomataceae in the Germplasm Resources Information Network (GRIN), USDA , ARS , National Genetic Resources Program. National Germplasm Resources Laboratory, Beltsville, Maryland.
• James R. Shevock: Jepson Manual .
• Photos