Plant biol (Stuttg) 2007; 9(6): 705-712
DOI: 10.1055/s-2007-965080
Research Paper

Georg Thieme Verlag Stuttgart KG · New York

Morphology and Anatomy of Shoot, Root, and Propagation Systems in Hoffmannseggia glauca

T. A. Kraus1 , M. A. Grosso1 , S. C. Basconsuelo1 , C. A. Bianco2 , R. N. Malpassi1
  • 1Morfología Vegetal, Facultad de Agronomía y Veterinaria, Universidad Nacional de Río Cuarto, Ruta 36 Km 601, 5800 Río Cuarto, Córdoba, Argentina
  • 2Botánica Sistemática, Facultad de Agronomía y Veterinaria, Universidad Nacional de Río Cuarto, Ruta 36 Km 601, 5800 Río Cuarto, Córdoba, Argentina
Further Information

Publication History

Received: October 2, 2006

Accepted: February 16, 2007

Publication Date:
31 May 2007 (eFirst)

Abstract

Hoffmannseggia glauca is a perennial weed that has tubers and root-borne buds. Some authors only consider root tubers without mentioning root-borne buds, while others consider that more anatomic studies become necessary to determine the origin of these structures and to interpret their behaviour. The objectives are: to study the growth form of the plant in order to analyze the ontogeny of its propagation organs, and to study its shoot and root anatomical characters that affect water conductivity. Hoffmannseggia glauca was collected in Argentina. Development of its shoot and root systems was observed. Shoots and roots were processed to obtain histological slides. Macerations were prepared to study vessel members. Primary and lateral roots originate buds that develop shoots at the end of the first year. In winter, aerial parts die and only latent buds at soil surface level and subterranean organs remain. In the following spring, they develop innovation shoots. Roots show localized swellings (tuberous roots), due to a pronounced increase of ray thickness and parenchymatous proliferation in the root center. Root vessel members are wider than those of aerial and subterranean shoots. Early development of an extensive root system, presence of root borne buds, anatomic and physiological specialization of innovation shoots, capability of parenchymatous rays to originate buds and tuberous roots, and high water transport efficiency in subterranean organs lead Hoffmannseggia glauca to display higher colonization potential than other species.