A Monograph of the Genus Calochortus

Abstract

The recent development of new techniques for the study of the biological entities which we term genera and species has created a renewed interest in taxonomy as a basic plant science. Modern taxonomy no longer concerns itself primarily with merely cataloguing, with appropriate binomials and brief diagnoses, the variants which do not fit into the pre-existing ^^ pigeon holes/' but is making a sincere attempt to understand the factors which make themselves evident through variation and speciation.The development of the monographic method of plant taxonomy is largely responsible for this change of attitude. The plant kingdom, as a whole, is so inconceivably vast, that it is only by the comparative study of a limited group of related entities that we are able to secure any understanding of the laws which must govern the entire assemblage of groups. It was with this fact in mind that the genus Calocliortus was selected as the subject of the present study.This genus is admirably suited to such an investigation. In ^An investigation carried out at the Missouri Botanical Garden in the Graduate Laboratory of the Henry Shaw School of Botany of Washington University and submitted as a thesis in partial fulfillment of the requirements for the degree of Doctor of Philosophy.

PHYLOGENY, CONCERTED CONVERGENCE, AND PHYLOGENETIC NICHE CONSERVATISM IN THE CORE LILIALES: INSIGHTS FROM rbcL AND ndhF SEQUENCE DATA

“…The suggestion that Clintonia may have arisen in southern China (based on a noncladistic analysis of karyotypic variation by Li et al 1996), if proven, would resolve the only conflict between the subcontinental and continental analyses and identify eastern Eurasia as the cradle of Liliaceae. standing taxonomic mystery regarding the closest relative of Calochortus (see Baker 1875; Bentham and Hooker 1883;Ownbey 1940;Cave 1941;Berg 1960;Chase et al 1995a;Stevenson and Loconte 1995;Tamura 1998a), in which a sister relationship to Tricyrtis had never been explicitly suggested. Berg (1960) did, however, discuss similarities in embryology between the two groups (e.g., a very long nucellus rest, early disruption of the nucellus, normal-type embryosac development), and recommended that Calochortus be transferred to a position near the tribes Tricyrteae or Uvularieae of Melanthiaceae.…”

“…The open habitats occupied by bulbous taxa in the core Liliales are characterized by high light availability and a short season favorable for photosynthetic activity. Bulbous taxa in the core Liliales grow mainly in Mediterranean scrub or temperate sclerophyll forests (with a brief period of favorable conditions following winter rains), in arctic and alpine tundra (with a brief period of favorable conditions between spring thaw and autumn snowfall), or as spring ephemerals in temperate deciduous forests (with a brief period of favorable conditions between spring thaw and canopy closure ;Raunkiaer 1934;Adamson 1939;Ownbey 1940;Woodcock and Stearn 1950;Stebbins 1974;Pate and Dixon 1982;Dahlgren et al 1985;Antos 1988;Givnish 1988). This contrasts with the forest habitats occupied by rhizomatous, shade-adapted taxa (e.g., Clintonia and Tricyrtis) that remain photosynthetically active through a long growing season beneath a closed canopy.…”

“…Storage organs are bulbs or rhizomes, flowers are visually showy or inconspicuous, fruits are capsules or berries, leaves are broad and reticulate-veined or narrow and parallel-veined (Dahlgren et al 1985;Phillips and Rix 1989;Chase et al 1995b). Variation in these characters has shaped traditional perspectives on relationships in the core Liliales (Baker 1875;Bentham and Hooker 1883;Ownbey 1940;Berg 1959Berg , 1962aCronquist 1981;Conover 1983;Dahlgren et al 1985;Conran 1989;Thorne 1992;Chase et al 1995b;Stevenson and Loconte 1995) and led many to believe that Calochortus and Liliaceae s.s. are each other's closest relatives. Morphological characters are often prone to convergence and other forms of homoplasy (Kadereit 1994;Soltis and Soltis 1995;Givnish and Sytsma 1997a).…”

Vegetation Description, Rare Plant Inventory, and Vegetation Monitoring for Craig Mountain, Idaho.

“…filaments; ovary linear, not winged, tapering to a persistent, trifid stigma; fruit linear-lanceolate, acuminate, 3-angled, erect; seeds straw-colored, strongly flattened with loose-fitting coats. N=7 (Ownbey 1940;Ownbey 1969). …”

“…Alternative taxonomic treatment: Many authors up to and including Ownbey (1940) have referred specimens of the related species CuZochortus eurycarpus to C. nitidw, causing confusion over the proper application of the latter name. Ownbey (1969) eventually clarified this situation.…”