272 Rydberg : Some Generic Segregations 



we must, if consistent, divide Zygadenus into at least three genera. 

 Briefly these may be distinguished as follows : 



Plant with a rootstock ; each petal and sepal with two glands. Zygadenus. 

 Plant with a bulb; each petal and sepal with a single gland. 



Ovary wholly superior ; gland obovate or semi -orbicular. Toxicoscordion. 



Ovary partly inferior ; gland obcordate. Antidea. 



Zygadenus Michx. Fl. Bor. Am. i: 213. 1803 

 This genus was established on a single species Z. glabcrrimiis 

 and the generic name will go with it. This species differs from all 

 that later have been included in the genus, in having a thick elon- 

 gated rootstock instead of a bulb and two distinct round glands 

 on each of the petals and sepals. As far as I know the genus 

 consists of only one species. 



Toxicoscordion gen. nov. 



Glabrous, more or less poisonous perennials with narrow linear 

 conduplicate leaves, yellowish racemose or paniculate flowers and 

 membrane-coated bulbs. Flowers perfect (in one species described 

 as polygamous, but as far as I know erroneously so). Petals and 

 sepals bearing a .single obovate or semiorbicular gland at or above 

 the base of the blade, in most species more or less clawed. Ovary 

 wholly superior. Stamens (except in one species) more or less 

 adnate to the base of the petals and sepals ; anthers subreniform, 

 confluently one-celled. Capsule 3-celled, 3-beaked, septicidal. 

 Seeds numerous. 



The first species known belonging to this group was published 

 under the name Amianthhun Nuttallii A. Gray ; but as this is 

 somewhat aberrant from the general type of the genus, I have 

 selected one of the most common species, Zygadenus intermcdms, 

 as the type. The following species belong here : 



1. T. intermedium; Z. intermedins Rydb.* 



2. T. venenosum (S. Wats.) ; Z. venenosns S. Wats. 



3. T. gramineum ; Z. gmminens Rydb. 



4. T. acutum ; Z. acntus Rydb. 



5. T. f alcatum ; Z.falcatus Rydb. 



6. T. paniculatum (Nutt.) ; Hclonias panicjdata Nutt. 



7. T. Nuttallii (A. Gray) ; AmiantJdnm Nuttallii A. Gray. 



*For citations and synonyms, see Bull. Torrey Club, 27 : 534-538. 1900. 



