remarkable in its natural family and its position is there- 
fore rather open to dispute. When first described by 
Ledebour in 1837 its author placed it in the genus 
Cotyledon, as understcod by Linnaeus, and named it 
C. oppositifolia. A few years later Ledebour, however, 
transferred it to the genus Umbilicus, as characterised 
by De Candolle in 1801, though to accommodate this 
‘Caucasus plant he defined a monotypic section Chias- 
tophyllum. Boissier, in 1872, followed Ledebour’s later 
treatment; Bentham and Hooker in 1865, however, 
found it preferable to merge Umbilicus as a whole in the 
genus Cotyledon. This treatment, which is followed here, 
renders it necessary to employ the earlier name, Cotyledon 
oppositifolia, proposed by Ledebour. 
Description.—Herb, perennial, glabrous, prostrate and rooting below, with 
above glabrous erect stems 6-10 in. high. Leaves opposite, decussate, more 
or less fleshy, shortly petioled, elliptic or ovate-elliptic, obtuse, crenate, 1-13 in. 
long, 3-14 in. wide, nearly flat or slightly concave, glabrous; petiole about 
2 in long. Racemes branched, spicate, many-flowered, arranged in a loose 
panicle; bracts linear, acute, 51; in. long. Flowers small, yellow, shortly 
pedicelled. Calya 5-partite ; segments ovate-oblong, somewhat obtuse. Corolla 
ellipsoid, 2-4 in. long, 5-fid; lobes erect, apiculate. Stamens 10; filaments 
inserted below the corolla throat. Carpels 5,4 in. long; nectariferous scales 
oblong. Capsules 5, apiculate, 
rt eens 
Tas. 8822.—Fig. 1, flower; 2, section of corolla, 
showing the stamens; 
3, carpellary whorl, showing the nectariferous scales : : 
—all enlarged. 
