68 COMPOSITE. 



/ 



112. COREOPSIS. Involucre of two distinct series of bracts, all commonly united at the 

 very base ; outer foliaceous, narrower, and usually spreading ; inner erect or incurved after 

 anthesis, more membranaceous, each series commonly 8 in number. Rays about 8, wanting 

 in one or two species. Disk-corollas with slender tube and funnelform or campauulate 

 5-lobed or 5-toothed limb. Akenes flat, or becoming nieniscoidal, orbicular to linear-oblong, 

 winged or wingless, truncate or emarginate at summit, bearing 2, rarely 3 or 4 naked (or 

 upwardly hispid) awns, or naked scales, or teeth, or sometimes wholly destitute of pappus. 



•i— -)— Eays fertile or neutral, or wanting : awns of the pappus when present retrorsely 

 barbed or hispid. 



++ Bracts of the involucre distinct, or united only at the common base. 



113. BIDENS. Akenes neither winged nor beaked, 2-5-awned ; the awns retrorsely hispid 

 or aculeolate, mostly persistent. Rays neutral (in one Mexican species styliferous), yellow 

 or white, sometimes wanting : no ring to the disk-corollas. 



114. COSMOS. Akenes slender and beaked: rays purple or rose color, in one species 

 orange-yellow : otherwise as Bidens ; the awns apt to be deciduous. 



115. HETEROSPERMUM. Akenes dimorphous; the outer with winged or callous 

 margin, mostly cymbiform ; inner narrower, attenuate upward, marginless ; these and some- 

 times the outer with 2 retrorsely barbed awns. Rays fertile : no ring to the disk-corollas. 

 Heads rather few-flowered. 



116. LEPTOSYNE. Akenes oval or oblong, truncate or emarginate, some of them 

 usually wing-margined or bordered. Rays pistillate and often fertile, occasionally neutral. 

 Disk-corollas with slender tube girt at summit or near it by a bearded or naked ring, a 

 dilated throat, and 5-lobed limb. 



++ +-I- Bracts of the inner involucre iinited into a cup. 



117. THELESPERMA. Involucre of Coreopsis; but the bracts of the inner connate to 

 or above the middle, tlesliy below, their free summits more membranaceous and scarious- 

 margined ; outer of shorter and narrow somewhat foliaceous spreading bracts, connate at 

 base with the inner. Chaffy bracts of the flat receptacle wliolly white-.scarious, witli a 

 2-nerved midrib, otherwise nerveless, deciduous with the akenes. Rays about 8, neutral, 

 cuneate-obovate, or in some species wanting. Disk-corollas with long and slender tube, 

 abrupt campauulate or cylindrical throat, and linear to ovate spreading lobes. Anthers 

 wholly exserted. Style-appendages tipped with a cusp or cone. Akenes slightly obcom- 

 pressed or terete, narrowly oblong to linear, marginless, beakless, attached by a broad 

 callus, at least the outer ones tuberculate, papillose, or rugose ; the abrupt summit crowned 

 with a pair of persistent and stout awns or rather scrfles, the margins of which are retrorsely 

 hispid-ciliate, or sometimes pappus obsolete or wanting. Leaves opposite. 



Subtribe VII. Galinsoge^. Pappus pluripaleaceous, and akenes commonly turbinate 

 and 5-angled : otherwise nearly as Verbcsinece. Receptacle chaffy throughout : other- 

 wise as HelenioidecB. Ours all herbs, and leaves except in Galinsoga alternate and 

 entire. 



* Bracts (chaff) of the receptacle concreted, coriaceous or cartilaginous, persistent, forming 

 deep alveoli, resembling honeycomb, in which the akenes are enclosed : rays neutral. 



118. BALDWINIA. Heads many-flowered, conspicuously radiate. Involucre imbricated, 

 shorter than the convex disk ; its bracts small, coriaceous and partly herbaceous. Disk- 

 corollas with a short soon indurated tube, above cylindraceous, 5-toothed ; the teeth glandu- 

 lar-puberulent. Style-appendages truncate and penicillate, with a subulate tip. Akenes 

 turbinate, silkj'-villous : pappus of 7 to 12 nerveless thin-scarious palea. 



* * Bracts of receptacle distinct, liuear or filiform, rigid : rays none : palea; of the pappus 

 thin-scarious, nerveless. 



119. MARSHALLIA. Heads many-flowered, homogamous. Involucre one or two series 

 of narrow and equal herbaceous liracts. Receptacle at length conical. Corollas with 

 a filiform tube and the limb 5-parted into linear lobes. Style-branches truncate at apex. 

 Akenes turbinate, 5-costate : paleai of the pappus 5 or 6, ovate or lauceolate-deltoid, acute or 

 acuminate, nearly entire and naked. 



