Vol. 51 ’ No 9 
BULLETIN 
TORREY BOTANICAL CLUB 
SEPTEMBER, 1924 
Some Senecioid Genera—I 
P. A. RYDBERG 
Cacstrma L. Sp: Pl: 
Bentham & Hooker in their Genera Plantarum included in 
Senecio quite a number of genera proposed by various authors, 
among them Ligularia Cass., Cacaha L., Psacalium Cass., 
Kleinia Haw., etc. I shall confine myself in this paper to the 
genera of North America only, and especially those species 
which have been known as members of the so-called genus 
Cacalia. 
The first questions which present themselves are: Can this 
genus be separated from Senecio and what is the reason for merg- 
ing it in that genus? The characters by which it is usually 
distinguished are the white or cream-colored, not yellow, disc- 
corollas, the absence of ray-flowers, and the more elongate corolla- 
lobes. Several of the true Senecios have cream-colored disc- 
corollas, and quite a number of them are rayless. A few species, 
usually included in Cacalia, have short corolla-lobes. There is 
no reason therefore why the genus Cacalia, as usually instituted, 
should be excluded from Senecio. The trouble has arisen because 
botanists have included in Cacalia several different types which 
can easily be distinguished from each other and from Senecio 
if considered separate but not if taken as an aggregate. 
If these groups can be separated and segregated as distinct 
genera, another question arises: To which group should the name 
Cacalia L. be applied? 
In Species Plantarum the genus Cacalia contains ten species, 
divided in two groups. The type must be sought in the second 
group, for at the end of the genus Linnaeus made the statement 
that the two genera, Cacalia and Kleinia, should be united. 
[The BuLLETIn for August (51; 335-368) was issued August 22, 1924.] 
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