96 Systematik und Pflanzengeographie. 



und Abbildung (Ic. Rar. tab. 3G6) absolut nicht übereinstimmen. 

 Der neuesten Bearbeitung von Alida M. Cunningham (Proc. 

 Ind. Acad. Sei. 1896 p. 190—207; 1897) vermag sich Vert. 

 nicht anzuschliessen. 



Auf Grund sehr reichlichen Herbarmaterials kam er zu einer 

 Gruppiruug der Arten, aus der folgendes mitgetheilt sein mag : 



§ I. Flowers all perfect; lobes of the corolla not closed over the pyxis ; 

 stamens four. 



* Kood perennial, biennial, or annual in P. deeipiens .... etc. 

 ** Root annual ; the petioles dilated at their bases ; flowers hetero- 

 gonous, in the majority of intividuals cleistogamous ; the lobes of the 

 oper corolla wide-spread, nearly equalling the tube ; seeds solitary in 

 the two cells, deeply hollovved on the face. 

 Bracts linear to lanceolate. 



Bracts aristate, two or more times as long as the flowers. 

 Spikes more or less compact ; plant dark green. 



Spikes large, 20-many flowered. 1. P. aristata. 



Spike small, 2 — 2Ü-flowered. 2. P. aristata Nutaüii. 



Spikes more or less interrupted ; plant light green. 



3. P. spinulosa. 

 Bracts not aristate, not over two times as long as the flowers. 

 Bracts linear-subulate to narrowly lanceolate, narrow at 

 the base. 



Spikes narrow - cylindrical ; whole plant-white-woolly, 



light green. 4. P. Purshii. 



.Spikes narrow cylindrical, at leugth interrupted whole 



plant silvery-silky, dark green. 5. P. argyrea. 



Spikes thick, conspieuous on aecount of the large corollas ; 



plant villous, dark green. 6. P. Helleri. 



Bracts lanceolate or triangulär, wide at the base. 



Plant erect ; spikes crasse. 



Plant glabrous or nearly so, dark green. 



7. P. Wriqhtiana. 

 Plant villous, bright green. 



Bracts more than 3 mm long; sepals scarious, with 



brown midribs. 8. P. dura. 



Bracts not more than 3 mm long; sepnls herba- 



ceous, green. 9. P. inflexa. 



Plant spreeding, spikes delicate. 10. P. lanatifolia. 



Bracts oblong to ovate or orbieular. 



Plant villous; bracts a. long as the sepals or (insiter) equalling 

 the calyx. 



Bracts with brown midribs ; petals with longitudinal brown 

 streaks. 



Plant spreading, stout. 11. P. insularis. 



Plaut erect, stender. 12. P. brunnea. 



Bracts with green midribs ; petals white or tawny, darker at 

 the base only. 



Plant shortstemmed ; spikes villous; seeds brown. 



13. P. fasligiata. 

 Plant acaulescent ; spikes pubescent; seeds yellow. 



14. P. scariosa. 

 Plant pubescent or glabrate ; bracts one half as long as the 

 sepals or shorter. 



Leaves linear, 3-ribbed; scapes dilated or stout; spikes 

 several-flowered. 15. P. ereeta. 



Leaves linear-subulate, not ribbed; skapes filiform; spikes 

 2— 4(— 5>flowed. 16. P. tetrantha. 



Ueber Synonymie und geographische Verbreitung der einzelnen 

 Arten mag folgendes mitgetheilt werden : 



