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ROBINSON AND GREENMAN. — GENUS MIKANIA. 11 



l)uberulent or glabrous. Pappus of many seta; in a single row, mostly 

 about equalling or somewhat exceeding the acheue, bright white or more 

 commonly sordid, fuscous, or rufous. — Spec. iii. 1742; DC. Prodr. 

 V. 187, vii. 270; Benth. & Hook. f. Gen. ii. 246; Hoffm. in Engl. & 

 Prantl, Nat. Pflanzenf. iv. Ab- 5, 140. WiUugbceija, Neck. Elem. i. 82. 

 Corymanthelium, Kuuze, •Linnoea, xx. ID. — Mostly slender shrubby or 

 herbaceous twiners or " rarely erect." Leaves opposite, usually ovate, 

 cordate or hastate, and petiolate. Inflorescence spicately, raceraosely, 

 or corymbosely paniculate. A genus of some 175 good species nearly 

 confined to Tropical or Subtropical America. M. scandens is also 

 widely distributed in the United States and in the warmer parts of the 

 Old iVorld. 



Subgenus 1. Cylindrolepis. Truncate scales of the involucre not 

 at all imbricated but strongly involute, each completely surrounding a 

 flower. 



1. M. globosa, Coulter. Glabrous or nearly so: leaves ovate, 

 thickish, undulate-dentate, acuminate, rounded at the base, 5-nerved from 

 near the base: heads in dense globose clusters; these in lateral or ter- 

 minal panicles: each of the four flowers completely enveloped in an 

 involucral scale : mature achenes not seen. — Bot. Gaz. xx. 46, where 

 also called WillugbcBya globosa. — Santa Rosa, Guatemala, altitude 4,000 

 feet, Heyde ^ Lux (no. 3430 of Dounell Smith's sets). A noteworthy 

 species differing much in its involucral scales from any other known to 

 us. It is said by Professor Coulter to resemble closely M. smilacina in 

 " habit and structure." The likeness, however, does not extend to the 

 heads, which are here completely divided into four compartments by the 

 intrusion of the involute edges of the scales ; while in M. smilacina the 

 involucre is normally imbricated. 



Subgenus 2. Imbricate. Scales of the involucre imbricated. 

 § 1. Heads spicately or racemosely arranged on the opposite spread- 

 ing branches of ample pyramidal panicles. 



* Heads pedicelled. 



2. M. Houstonis, Willd. Glabrous climbing shrub, with ovate 

 acuminate entire petiolate leaves. — Spec. iii. 1742 ; DC. Prodr. v. 190. 

 — S. Mexico, Vera Cruz, Houston, and (ace. to Hemsl.) " Linden, no. 

 1169; Yucatan and. Tabasco, Johnson, no. 25 ; Guatemala, Las Esca- 

 millas, Hartweg, no. 535 ;.Chojoja, near Mazatenango, Bernoidli, no. 100; 

 Panama, Barbacoas, S. Hayes." The only plants in Herb. Gray agreeing 

 with the character of this species are Ervendherg's nos. 87, 222, from 

 Wartenberg, Huasteca, Mexico. 



