PAO ir eiateees me 
MUHLENBERGIA _ 
A. A. HELLER, Editor 
BOTANICA A 
Ga RDEN. 
Los Gatos, CALIFORNIA, SEPTEMBER 26, 1908 
4 ; ‘SYNOPSIS OF THE CALIFORNIAN SPECIES OF 
Ye CONVOLVULUS 
By HOMER DOLLIVER HOUSE 
The center of distribution of the genus Convolvulus in 
North America is California, which possesses 26 species out of a 
total of about 43 known to North America. Calystegza R. Br. 
(Volvulus Medic.), has been recognized by several authors as dis- 
tinct from Convolvulus and with Convolvulus sepium as its 
type. Inasmuch as Calystegza is one of the “genera conser- 
vanda” of the Vienna Code, it is important to point out the fact 
that in the 5th edition of the Genera Plantarum (1752), Lin- 
naeus cites J/. 77 of Tournefort, which is an excellent figure of 
Convolvulus major albus, the Convolvulus sepium of the Species 
Plantarum (1753). This species must therefore be recognized 
as the type of Cozvolvulus, and Calystegza and Volvulus remain 
as pure synonyms of it. 
The recognition of Calystegza has not been very general in 
Ainerica, doubtless because among the Californian species every 
gradation may be found from the closely investing bracts of C 
occidentalis to bracts shorter than the calyx and not closely in- 
vesting it, as in C. Greene, bracts which are distant and simu- 
1 lating the leaves, as in C. fudcratus and C. gracilentus, or bracts 
varying in size and distant from the calyx, as in C. purpuratus 
» and C. longipes. 
MLC 
(49) 
