AvausT 16, 1906] MANUAL OF THE PHILIPPINE COMPOSITAE 151 
52. SENECIO LINN. 
Chiefly annual or perennial herbs (a few tropical species 
shrubby or even arborescent), with basal and alternate leaves. 
Inflorescence corymbose or paniculate; heads heterogamous, 
yellow or purple, with tubular and ligulate or only tubular 
flowers; involucre cylindric, its bracts distinct or united at 
the base; receptacle flat, mostly naked, often honeycombed, 
ligulate flowers when present pistillate and fertile; disk flowers 
perfect, fertile, tubular corolla 5-segmented; anther bases 
entire or slightly sagittate; style arms spreading or recurved; 
achenes terete, or the ligulate somewhat compressed; 5 to 
10-ribbed, papillose or canescent; pappus of many capillary 
bristles. 
It is not only the largest genus of the Compositae but 
the largest in species of all the Phaenogamous plants. Its 
geographical distribution is universal throughout the globe. 
They are ubiquitous,—in the tropics as well as in the arctics, 
in the mountains and in the deserts, on borders of streams, 
along seacoast, in swamps—everywhere these denizens are 
met. They are most varied and abundant in the temperate 
regions. None of them have a wide area, but most of them 
are rather abundant in their confined limits. A few of the 
extreme northern species are common to both the old and 
new worlds. This genus has over 1200 more or less local- 
ized species whose center of geographical distribution is in 
the high latitudes of the northern hemisphere and in the 
alpine regions of southward extending mountains. Notwith- 
standing the fact that over 40 generic names have been 
proposed fron time to time for different sections, still the 
entire group remains intact and forms indeed a closely re- 
lated series. 
Leaves obovate, irregularly toothed or lobed. 
i. S. benguetense. 
Leaves otherwise. 
Flowers yellow. 
Leaves linearly triangular, acuminate. 
2. S. coníusus. 
