36 CRUCIFER^. [ALYSSUM. 



12*. ALTS' SUM, L.- 



Herbs or small shrubs, often covered with stellate down. Leaves 

 scattered or crowded, entire. Flowers small, white or yellow. Sepals 

 short, equal. Petals short, entire or 2-fid. Filaments sometimes toothed 

 or appendaged. Pods short, very various in form ; valves flat, concave or 

 convex; septum entire or perforate ; stigma simple. Seeds 3.-\Q ; radicle 

 accumbent. DISTRIB. N". and W. Asia and N. Africa; species 80-90. 

 ETYM. obscure. A polymorphous genus, almost every organ varying ; 

 hence 10 genera have been made out of it. 



A. CALYCI'NUM, L, ; pubescent with appressed stellate hairs, leaves 

 linear-spathulate, sepals persistent, petals yellow, pods suborbicular. 

 Cultivated fields, rare and sporadic in England, Scotland, and Ireland ; (an 



alien, Wats.} ; fl. June- Aug. Annual, hoary. Stem branched at the base ; 



branches 3-8 in., rigid, ascending. Leaves J-f in., few, scattered, obtuse. 



Flowers small ; filaments with 2 teeth at the base. Fruiting racemes elongate. 



Pods T ^ in. diam., very numerous, on short stiff spreading pedicels, nearly 



orbicular, turgid with broad thin flat margins, notched at the tip ; style very 



short; seeds 1-2 in each cell, narrowly winged. DISTRIB. Central and 



S. Europe, W. Asia. 



A. MARIT'IMUM, L. ; pubescent with appressed 2-partite hairs, leaves 

 linear, sepals deciduous, petals obovate white, pods obovoid-orbicular. 

 Koni'ga, Br. ; Lobula'ria, Desv. ; Gly'ce, Lindl. 

 Waste places near the sea ; in England and the Channel Islands ; (a denizen, 



Wats.) ; fl. June-Sept. Annual or perennial. Rootstock prostrate. Stem 



4-10 in., ascending, leafy. Leaves 1-lf in., T V-f ,'in. broad, subacute. 



Flowers small, odorous ; filaments all simple. Pods ^ in. without a border ; 



pedicel slender, spreading; valves convex, 1 -nerved ; cells 1-seeded; style 



slender. DISTRIB. Maritime S. Europe and W. Asia. 



13. COCHLEA'RIA, L. SCURVY-GRASS. 



Perennial herbs. Leaves entire or pinnate. Flowers small, white. Sepals 

 short, equal, spreading. Petals shortly clawed. Pods sessile or shortly 

 stalked, oblong or globose ; valves turgid, reticulate ; septum often im- 

 perfect ; stigma simple or capitate. Seeds few or many, 2-seriate, not 

 margined, tubercled ; cotyledons accumbent. DISTRIB. Temp, and Arctic 

 regions, chiefly littoral or Alpine; species 25. ETYM. cochlear, from the 

 spoon-like leaves. The native British species form a well defined group of 

 variable littoral plants, confined to N.W. Europe and the Arctic regions ; 

 but some exotics have the habit of Nasturtium. 



* Valves with a dorsal nerve. 



1. C. officina'lis, L. ; radical leaves cordate, pods sub globose, valves 



reticulate, style very short. C. polymor'pha, Syme. 



Sea-shores and high mountains, N. to Shetland ; Ireland ; Channel Islands ; fl. 

 May-Aug. Stems many, 4-10 in., glabrous, fleshy, ascending from the 

 perennial rarely biennial rootstock. Flowers J-^ in. diam. Pods -^ 



