Ranunculus rhomboideus

Ranunculus rhomboideus Goldie
Ranunculaceae
	5 - 22 cm  -     -
	IV, V, VI 3A / f8da21
Taxonomy
Divisio: Magnoliophyta Subdivisio: Magnoliophytina Classis: Ranunculopsida Subclassis: Ranunculidae Superordo: Ranunculanae Ordo: Ranunculales

Ranunculus rhomboideus is a perennial with lemon yellow flowers.

Naming

Ranunculus rhomboideus was described by John Goldie. The name is considered as validly published.

Taxonomy

Ranunculus rhomboideus is a species in the genus Ranunculus which contains approximately 432 to 2271 species and belongs to the family of the Ranunculaceae (Buttercup Family). The type species of the genus is Ranunculus auricomus.

Characteristics

Growth

The perennials reach heights of 5 to 22 centimetres.

Leaves

Ranunculus rhomboideus is deciduous. The mid-green, simple leaves are basal. They are ovate, crenate and petiolate.

Flowers and Fruits

Ranunculus rhomboideus produces panicles of yellow five-stellate flowers from April to June.

The perennials produce nutlets.

Distribution

Ranunculus rhomboideus is native to eastern Canada, Manitoba, Montana, North Dakota, South Dakota, Nebraska and the central Northeast of the US.

Cultivation

The perennials prefer a sunny to half-shady situation on moderately moist soil. The substrate should be sandy-loamy or gritty-loamy soil.

Maintenance and Propagation

Propagate by sowing just before seeds ripen. Germination may take some time.

Poisonousness

The sap may irritate the skin

 Please read the health issues note! 

Pests and Diseases

Honeydew, galls and distorted leaves are a sign for an infestation with aphids. Use an insecticide or control biologically , e.g. with parasitic wasps or predators such as Aphidoletes aphidimyza.

A powdery white coat on the plants indicates an infection with powdery mildew. Remove affected plants and apply a fungicide. To prevent infection improve ventilation, keep the roots moist and do not water the plants from above.

Gnaw marks and slime trails indicate a problem with slugs. Prevent infestation by improving hygiene and by regularly working the soil. In case of an infestation use slug pellets or nematodes to control pest. Handpicking the slug also helps, do this preferably in the evening hours.

Literature

• Walter Erhardt, Erich Götz, Nils Bödeker, Siegmund Seybold: Der große Zander. Eugen Ulmer KG, Stuttgart 2008, ISBN 978-3-8001-5406-7. (Ger.)
• Christoper Brickell (Editor-in-chief): RHS A-Z Encyclopedia of Garden Plants. Third edition. Dorling Kindersley, London 2003, ISBN 0-7513-3738-2.

Non-commercial Links

• Ranunculus rhomboideus at the United States Department of Agriculture
• Ranunculus rhomboideus in the Flora of North Americaes:Ranunculus rhomboideus