Origin and Development of the Composites. i 2 1 
calyculus, which is frequently present. The members of the caly- 
culus may be few and very small, as in Senecio vulgaris, S.Doria, etc., 
hut even in these species the number is sometimes as many as 
eight; or the calyculus may be multiseriate with the inner members 
almost equalling the periclinal bracts as in S. paniculatus ; or there 
may be no calyculus. A multiseriate calyculus of 20-40 leaves 
occurs in S. lavandulcefolius : other similar cases are the species of 
the section Leptolobi of Harvey and Sonders. 
The involucre in most of the genera of the Senecioninae is 
similarly uniseriate, with or without 3 . calyculus ; even in this sub¬ 
tribe, however, the involucre rapidly becomes biseriate, as in 
Arnica spp. and Doronicum , or triseriate as in Bartlcttia, or multi¬ 
seriate as in Melalema and Culcitium , or as in Eriothrix the 
involucral bracts may be almost indistinguishable from the densely 
crowded, reduced leaves of the stem. Culcitium is an interesting 
genus, as it differs from Senecio only in the multiseriate involucre, 
which on larger scale closely resembles that of 5. paniculatus in the 
gradual diminution in the size of the outer involucral members. As 
is usually the case where an artificial distinction is made, the two 
genera Senecio and Culcitium pass into each other by inter¬ 
mediate species which have been placed sometimes in one genus 
and sometimes in the other. Indeed, a new genus, Shafera, has 
been founded (5) which differs only in the 3-4-seriate involucre 
and obtuse style branches, and which is regarded by its author 
as intermediate between Senecio and Culcitium. It seems probable, 
therefore, that the multiseriate involucre in the Senecioninae is due 
to a development of the calyculus, the pericline remaining uniseriate. 
The Tussilagininae are usually uniseriate and the Liabinae 
multiseriate; the Othonninae are uniseriate and are characterised 
by the greater development of the tendency to connation which is 
present in Senecio. 
Cichoriece. The involucre in this tribe is very varied; frequently 
the pericline is uniseriate, with a well developed, more or less 
foliaceous calyculus in one to many rows. The progressive aggrega¬ 
tion of the cauline leaves to form the calyculus is occasionally seen in 
the dandelion. The sub-tribes are again indistinguishable on this 
character, but the structure of the involucre is closely allied to that 
of the Senecioninae. 
Calendulece. Here the involucre is usually uniseriate with or 
without a calyculus but is sometimes triseriate in Osteospermum, 
where the calyculus may equal or may be smaller than the 
pericline, 
