78-3 
Description.*—“ FYowers in an involucrate head on a simple receptacle, 
5-merous, or sometimes 4-merous; with /odes of the epigynous corol/a valvate in 
the bud; s¢amensas many as corolla lobes and alternate with them, inserted on the 
tube ; axzthers connate into a tube (syngenesious); s¢y/e in all fertile flowers 2-cleft 
or lobed at the summit and bearing introrse-marginal séigmas ; ovary 1-celled, a 
single anatropous ove erect from the base, becoming an exalbuminous seed with 
a straight embryo, the inferior radicle shorter and narrower than the cotyledons ; 
the fruzt an akene. Tube of the calyx wholly adnate to the ovary; its 7mé none, 
or absolute, or developed into a cup or teeth, scales, awns, or capillary bristles. 
Corolla with nerves running to the sinuses, then forking and bordering the lobes, 
rarely as many intermediate nerves. Anthers commonly with sterile tip or append- 
age; the cells introrse, discharging the pollen within the tube; this forced out by 
the lengthening of the s¢y/e, which in hermaphrodite and male flowers is commonly 
hairy-tipped or appendaged. Pollen-grains globose, echinulate, sometimes smooth, 
in CIcHoRIACE& 12-sided. Leaves various; no true stipules. Development of the 
flowers in the head centripetal; of the heads when clustered or associated, more 
or less centrifugal, 7. ¢., heads disposed to be cymose. Yuice watery, in some 
resinous, in the last tribe milky. 
“ Heads homogamous when all its flowers are alike in sex; heterogamous when 
unlike (generally marginal flowers female or neutral, and central hermaphrodite or 
by abortion male); axdrogynous when of male and female flowers; monarcious or 
dicecious when the flowers of separate sexes are in different heads, either on same 
or different plants; radiate when there are enlarged ligulate flowers in the margin ; 
wholly Zgwate when all the flowers have ligulate corollas, désco’d when there are 
no enlarged marginal corollas. When these exist they are sometimes called the 
vay ; the other flowers collectively occupy the disk. The head (compound flower 
of early botanists), in Latin capitulum, is also named anthodium. Its involucre 
(periclinium of authors) is formed of separate or sometimes connate reduced leaves, 
7. e., bracts (squame or scales); the innermost of these bracts subtend the outer- 
most or lowest flowers. The axis within or above these is the receptacle (clinan- 
thium), which varies from plane to conical or oblong, or even cylindrical or subu- 
late. When the receptacle bears flowers only it is naked, although the surface 
may be alveolate, foveolate or merely areolate, according as the insertion of the 
ovaries or akenes is surrounded or circumscribed by honeycomb-like or lesser 
elevations, or, when these project into bristles, slender teeth or shreds, it is fimbril- 
late ; it is paleaceous when the disk flowers are subtended by bracts; these usually 
chaff-like, therefore called pale, chaff, or simply bracts of the receptacle. In place 
of calyx-limb there is more commonly a circle of epigynous bristles, hairs or awns ; 
the pappus, a name extended to the calyx-limb of whatever form or texture ; its 
parts are bristles, awns, palae, teeth, etc., accordin gto shape and texture. Corollas 
either all ¢udu/ar (usually enlarging above the insertion of the stamens ‘into the 
throat, and 4 to 5-lobed at summit, mostly regular), or the marginal ones strap- 
shaped, 2. ¢., Higulate, the elongated limb (4igule) being explanate, and 3 to 5-toothed 
* Luse Prof. Gray's full description of the order from the volume above referred to, Vol. L., pt. 2, 48. 
