212 POLYGONACE AE 



Involucres sessile; leaves basal, petioled; bracts sessile, elliptic; 



scapose annuals. XIX. Puberula. 



Involucres peduncled; leaves and bracts similar, verticillate. 

 Imear; caulescent annuals. XX. Spergulina. 



Perianth herbaceous, closely investing the achene; involucre divided 

 to near the base; leaves spatulate; caulescent annuals. 



^ . XXI. Salsuginosa. 



I. Alata. 



Involucres hairy, 3-3.5 mm. long and 1.5-2 mm. wide; stem and leaves manifestly hirsute 

 and tomentose. i ^ alatum 



Involucres glabrous. 2-2.5 mm. long and of the same width; stem and leaves nearly 

 glabrous. . 2. E, triste, 



II. Erlantha. 



Perianth whitish; style hairy at least to the middle. 3 E Jamesii 



Perianth yellow; style hairy only at the base. 



Involucres 6-8 mm. long; leaf-blades oblong or oblanceolate. 4. E Bakeri 



Involucres 9-10 mm. long; leaf-blades suborbicular to oval. 5. E. arcuatum. 



III. Flava. 



Perianth (externally) pubescent throughout. 



Involucre elongated-obconic. 6-8 mm. long. 6 E Piperi 



Involucre turbinate, 4-5 mm. long. 



Stipe-like base of the perianth very short: old leaf-bases permanently tomentose. 

 I^eaf-bases thickened; perianth copiously pubescent; leaf-blades silky above; 



involucres usually several. 7. E. flavum. 



Leaf-bases not thickened; leaf-blades sUghtly floccose above; involucres few. 

 Perianth 6-7 mm. long. 8. E. chloranthum. 



o*- , Perianth about 4 mm. long. 9. E. poluphullum. 



Stipe-hke base of the perianth slender; old leaf-bases glabrous. 



Perianth pubescent at the base only. 11. E. androsaceum. 



IV. Caespitosa. 



Involucres with comparatively short, ovate, merely spreading lobes, long-peduncled ; 



leaves imear or nearly so, revolute; stems short, leafy. 12. E. thurnoides 



Involucres with long reflexed lobes. uiymuiati^. 



Densely cespitose, subacaulescent ; involucre solitary 



Perianth in flowers 3-4 mm. long. 13. e, caespitosum. 



r.o,?li^^J^ in flowers 2 mm long. 14. E. andinum. 



Caulescent, suff ruticose ; involucres 1-5. 



Perianth greenish yellow, 6-8 mm. long; leaves spatulate or oblanceolate. 



Perianth ocliroleucous. 5 mm. long; leaves linear or hnear-oblanceolate!^^^^ 



16. E. fasciculi folium, 



^ . V. PYROL.AEFOLIA. 



One species. 17, ^ pyrolae folium, 



^ , , , , ^ , VI. Umbellata. 



Leaf-blades ovate or cordate. IS e comno^itum 



Leaf-blades from obovate or orbicular to oblanceolate. compositum. 



Involucres soUtary. ^ io 7U rnruri 



Involucres several, umbellate. ^orceru 



Perianth deeply yellow. 



Leaves not densely tomentose beneath. 



Umbels simple; leaves spatulate. 20. E. neglectum 



Umbels more or less compound; leaves oblanceolate. 



Leaves densely tomentose beneath. 



Inflorescence more or less compound. 22. E. stellatum 



Inflorescence simnje. • 



Leaf-blades obovate-spatulate or oval; perianth 6-7 mm. long. 



I ^^r Ki„^ u 1.- ^ , ^^- E. umbellatum. 



Leaf-blades rhombic-ovate or rhombic-oval ; perianth 7-8 mm. long. 



Perianth ochroleucous, in age turning purpUsh rose-colored " ' ^^ ^'^^"' 

 Scape naked up to the umbel; leaves spatulate 



Perianth about 6 mm. long; leaf-blades spatulate-oblong or eUiptic, glabrous 



above at maturity. 25 E subalpinum 



Perianth about 8 mm. long; leaf-blades oval or ovate! permanently tomen- 

 uose aDov^e. 26 E aridum 



Scape with at least one whori of leaves below the umbel; leaf-blades oblanceo- 



*^^®* 27. E. heracleoides, 



VII. Lachxogyna. 



Leaves^and s^pe^siU^^^ elongate. 1 dm. high or more; perennials with a taproot 



Inflorescence irregularly branched. oR F Inrh7ionunn7n 



Inflorescence subcapitate. 29 E Tet^nei^r^^^^ 



Leaves lanate, subsessile obtuse; scape short, less than 3 cm. long, or none; pulvinate- 



cespitose perenmals; mvolucres capitate. ^^^c. i^uivi xcttc- 



