Ord. 4.] TETRANDRIA TETRAGYNIA. 35 



without lateral ribs at the base. Involucrum three-flowered, 

 with seven ovate segments. Stem ascending-. 

 Walls and rubbish. If. 6 — 9. Stems annual, reddish. L. dark-green. 



* 77. ISNARDIA. Isnardia. 



1. I. palustris, Suppl. 2593. (Marsh Isnardia.) 



Ponds and watery pi. 0. 7. Floating, smooth. L. opposite, 

 ovate, bright green, succulent. Fl. small, green, solit. 



78. ALCHEMlLLA. Lady's Mantle. 



1. A. vulgaris, 9. 597. (Common L.) Leaves lobed, plaited. 

 High and dry past. 1[.6, 7. Stems 4 — 8 in. Fl. green, in termin. dust. 



2. A. alp'ina, 4. 244. (Alpine L.) Leaves fingered, serrated; silky 



at the back. 

 Alpine rocks. "U . 7. L. of a bright silvery hue beneath ; fine 

 green above. Fl. green, in tufts. 



3. A. arvensis, 15. 1011. (Field L.) Leaves flat, three-lobed, cut. 



Fallow fields. ©.5 — 8. Spreading, about 3 in. Fl. lateral, green. 



TETRANDRIA DIGYNIA. 



79. BUFFoNIA. Buffonia. 



I. B. tenuifolia, 19. 1313. (Slender Buffonia.) 



Sea-coasts, now extinct. 0. 6. Stem erect. L. awl-shaped. 



TETRANDRIA TETRAGYNIA. 



80. fLEX. Holly. 



1. I. Aquifolium, 7. 496. (Common H.) Leaves ovate, acute, 

 spinous and wavy. Flowers axillary, somewhat cymose. 

 Hedg. and bushy pi. T? . 5. A handsome evergreen tree. Fl. white. 



81. POTAMOGeTON. Pond-weed. 



1. P. nutans, 26. 1822. (Broad-leaved P.) Upper leaves oblong- 



ovate, stalked, floating, coriaceous ; lower ones linear, membra- 

 nous, sessile. 

 Pools and ditches. If. 7. Stem branched, immersed. Spike raised. 



2. Y.heterophyllum, 18. 1285. (Various-leaved P.) Upper leaves 



elliptical, stalked, floating, slightly coriaceous ; lower ones lance- 

 olate, membranous, sessile. Flower-stalks swelling upward. 

 Pools and ditches. %.l — 9. Much smaller. Sjrikes dense, about 1 in. 



3. P '. perfoliatum, 3. 168. (Perfoliate P.) Leaves heart-shaped, 



clasping the stem, uniform, all submersed. 

 Pools and riv. If. 7, 8. L. pellucid, olive-colour. Spikes alone 

 emersed. 



