NORTH AMERICAN FLORA 



[Volume 24 



XI. Urceolatae 



Calyx-lobes half as long as the tube; bracts scarious-margined ; petals 3. 

 Stem branched from the base, 1-1.5 dm. high; bracts not longer than 



the calyx. 50. P. urceolata. 



Stem simple below, branched above, about 3 dm. high; bracts longer 



than the calyx. 51. P. Barberi. 



Calyx-lobes one fourth as long as the tube; bracts not scarious-margined; 



petal apparently single. 52. P. lucida. 



XII. POLYGONOIDES 



Leaflets reflexed; flowers 1 cm. long; spikes dense, thick, 1 cm. thick or 



more. 53. P. fissa. 



Leaflets not reflexed; flowers less than 1 cm. long; spikes 5-7 mm. thick. 



Leaflets 3-7, linear or narrowly oblong. 54. P. polygonoides. 



Leaflets 7-21, broadly oblong-oblanceolate. 55. P. Bigelovii. 



XIII. Alopecuroides 

 Stem and leaves pubescent. 



Peduncles terminal; bracts nearly black, their hairs with pustulate 

 bases; leaflets obtuse or mucronate. 

 Bracts narrowly linear-lanceolate, inconspicuously or at least nar- 

 rowly scarious-margined. 

 Bracts broadly lanceolate, broadly scarious-margined. 

 Peduncles mostly opposite the leaves; bracts dark-green, their hairs 

 not with pustulate bases; leaflets mostly acute. 

 Bracts narrowly lanceolate, long-attenuate, longer than the calyx; 



lobes of the latter half longer than the tube. 

 Bracts broadly ovate-lanceolate, abruptly acuminate, equaling the 

 calyx; lobes of the latter about equaling the tube. 

 Stem and leaves glabrous. 



Spikes short, head-like, globose or nearly so. 



Leaflets filiform; bracts pubescent on the back. 

 Leaflets linear to oblong or cuneate; bracts glabrous on the back. 

 Bracts ovate, more persistent, perfectly glabrous. 

 Bracts lanceolate, early deciduous, ciliate on the margins. 

 Spikes elongate, cylindric. 



Bracts with light somewhat scarious margins; leaflets distinctly 

 glandular-dotted beneath. 

 Stem conspicuously glandular-warty. 

 Stem not conspicuously glandular-warty. 



Corolla mostly blue, with a white base; upper part of the 

 staminal tube strongly colored; upper portion of the 

 bracts with dark and glabrous back. 

 Corolla white or tinged with rose or lilac; staminal tube 

 wholly straw-colored; bracts pubescent throughout, 

 mostly pale. 

 Bracts almost black. 



XIV. Flavae 

 Plant pilose. 

 Plant glabrous or nearly so. 



XV. Similes 

 One species. 



XVI. ClTRIODORAE 



Calyx-lobes ovate or triangular, much shorter than the tube. 



Gland-dots on the lower surface of the leaves very inconspicuous, the 



terminal gland not larger. 

 Gland-dots on the lower surface of the leaves especially along the mar- 

 gins rather conspicuous, the terminal gland much larger, often 

 forming a kind of mucro. 

 Corolla purple; leaflets 3-5 mm. long. 

 Corolla dark-rose; leaflets 1.5-3 mm. long. 

 Calyx -lobes lanceolate, acuminate, about equaling the tube. 



Bracts with a short acumination which is not more than one fourth as 



long as the body; leaflets rounded at the apex; flowers sessile. 

 Bracts with a longer acumination which is half as long as the body; 

 leaflets acutish ; flowers often slightly pedicelled. 



56. P. pilijera. 



57. P. Townsendii. 



58. P. inconspicua. 



59. P. ervoides. 



60. P. filiformis. 



61. P. brachystachys. 



62. P. Lemmoni. 



63. P. coslaricana. 



64. P. leporina. 



65. P. alopecuroides. 



66. P. Thouini. 



67. P. flam. 



68. P. etata. 



69. P. similis. 



70. P. citriodora. 



71. P. polyphylla. 



72. P. roseola. 



73. P. cilrina. 



74. P. vernicia. 



XVII. Unciferae 



Stipules broad, semi-ovate or semi-sagittate, membranaceous-foliaceous, 



venose. 75. P. insignis. 



Stipules subulate to setaceous, not foliaceous. 

 Tail of the bracts about equaling the body. 



Slender annual. 76. P. caudala. 



Stouter perennial herb. 



