388 



MEMOIRS OF THE NEW YORK BOTANICAL GARDEN [Vol. 9, No. 3 



Stifftia Mikan. 



Stifftia chrysantha Mikan, Del. Bras. pi. 1. 1820. 



Stifftia parviflora D. Don, Trans. Linn. Soc. 16: 294. 1830. 



Stifftia uniflora Ducke, Rodnguesia 2: 157. 1936. 



There is some doubt that Stifftia uniflora is generically compatible with the 

 other two components of Stifftia^ yet it is more closely allied with them than to 

 other members of the Gochnatinae. These brief remarks will apply to the three 

 species as though they are congeneric. 



In general facies, Stifftia is easily distinguishable from Stenopadus (with 

 which it has been sometimes associated). It is a glabrous shrub with slender 

 branches, thin, elliptic, acute, slender-petioled leaves, and solitary large-heads 

 or smaller heads paniculately arranged. The flowers are more or less similar in 

 form to those of Stenopadus, but have more advanced vasculation, more highly 

 specialized pollen grains., 21 and more highly differentiated style-branches (as 

 noted in our "key"). 



Elsewhere it has been suggested that Stifftia (sensu lat.) constitutes a 

 discrete phyletic line anciently cut off from Stenopadus (as have been other 

 phyletic segregates, viz. Chimantaea, Stomatochaeta, and Quelchia), and now 

 (except Stifftia uniflora) occupies the trans-Amazon region of central and south- 

 ern Brazil. 



Stomatochaeta (Blake) Maguire & Wurdack, stat. nov. 



Stenopadus subgen. Stomatochaeta Blake, Bull. Torrey Club 58:490. 1931. 



Heads solitary, terminal, few-flowered (10-20 [30]); involucre strongly gra- 

 date; receptacle plane or shallowly convex, epaleaceous except for 2-4 very 

 narrow marginal pales, or in two species also with 1-4 additionally more cen- 

 trally placed pales; corollas with internal hirsute collars, otherwise glabrous, the 

 lobes stiffly erect, a lacking median vein, 2-4 times longer than the thin-textured 

 10-nerved tube; apical appendage of anthers sharply acute (ca. 3 mm long), caudal 

 appendage sagittate, the tails linear, adjacent ones connate but easily separable; 

 pollen grains yellowish, tricolpate, the furrows long-pointed; grains subprolate, 

 sulosilate, the polar axis 45-50/7.; styles asperulous toward the tip, the branches 

 ascending or erect, short, obtusish, 0.5 mm or less long; achenes 6 mm or less 

 long, glabrous, quadrangular, 10-nerved; annulus lacking; corona entire low (ca. 



0. 5 mm long) bordered externally by a ring of pilose hairs; pappus 4-6-seriate, 

 the setae flattened and free at the base, minutely upwardly barbellate. Shrubs; 

 leaves coriaceous with veins (except S. cylindricd) immersed; trichomes mal- 

 pigiiioid. 



TYPE: species: Stomatochaeta crassifolia (Blake) Maguire & Wurdack. 



Key to the Species to Stomatochaeta 



1. Microphyllous shrubs, with leaves normally 1-3 cm long, 2.5-20 mm broad, 



1-nerved or with lateral veins most obscure; involucre 6-7-seriate. 

 2. Leaves broadly to narrowly obovate (1.5) 2-3 (5) cm long, (0.7) 1.0-2.0 (3.0) 

 cm broad; petioles 1-3 mm long; achenes 3 mm long; phyllaries glabrous. 



1. Stomatochaeta condensata, 

 2. Leaves oblong to oblong-oblanceolate, 10-26 mm long; 2.5-9.0 mm broad 

 boat-shaped, strongly conferted, sessile; achenes 5-6 mm long; phyllaries thinly 

 pilulose. 2. Stomatochaeta cymbifolia. 



See Mem. N. Y. Bot. Gard. 9:441-452. 1957. 



