586 PATAGONIAN EXPEDITIONS I BOTANY. 



i. MENTZELIA Linn. 



Petals 5, plane, with no intermediate scales. Stamens 10-200. Ovary 

 i -celled, style filiform, mostly 4-cleft, its lobes twisted. Leaves alternate, 

 with hooked, but not stinging hairs. 



Species 46, chiefly in warm parts of S. Amer.; i in Florida. 



M. ALBESCENS Gris. (Gill. & Arn. sub Bartonia.} 

 Flowers large, showy, in a leafy panicle. Staminodes 5, petaloid, the 

 outer filaments becoming gradually broader, and the outermost sterile. 

 Stem with a white, shining epidermis. Leaves sinuately toothed. Cap- 

 sule naked, 3-valved. Seeds broadly margined. 



(S. United States ; Mexico ; Andes and through temp. S. Amer.) ; N. 



Patagon. 



2. LOASA Juss. 



Petals 5 (or 6-7), cucullate or cymbiform, mostly spreading, with as 

 many alternating scales, which bear 2-3 dorsal setae and are often appen- 

 daged. Staminodes 10, filiform, in pairs opposite the scales. Ovary i- 

 celled ; style subulate ; stigma acute or 3-cleft. Capsule 3-valved. 



Herbs, often with stinging hairs, and yellow flowers. 



KEY TO THE SPECIES. 

 A. Erect. 



b. Leaves pinnatifid, long-petiolate ; segments entire or parted, suboval. Flowers solitary, 



apical. patagonica. 



b2. Basal leaves bipinnatifid, long-petiolate, ultimate segments roundish ; upper leaves once- 



pinnatifid. Peduncles axillary, i -flowered. 



c. Hairs not stinging. argentina. 



c2. Hairs stinging. filicifolia. 



3. Leaves tripinnatipartite. Ultimate segments narrow. Flowers axillary. vuiltifida. 



l>4. Leaves basi-cordate, divided. 



c. Flowers few, subapical. Leaves 3-partite, and the segments 3-lobed. spegazzinii. 



C2. Flowers axillary. Leaves many-lobed. Petals with red base. tricolor. 



A2. Twining. Leaves bipinnatifid ; ultimate segments narrow. Flowers on terminal and axil- 

 lary peduncles. volubilis. 

 A^.. Decumbent-prostrate. Peduncles axillary, i-flowered. 



b. Leaves petiolate, subrotund, 3-5 -partite. muralis. 



b2. Leaves sessile, cordate-ovate, angular. prostrata. 



i. L. ARGENTINA Urb. & Gilg. (L. pinnatifida Gill, var gracilis.'] 



Nearly erect. Annual herb, with long, twining stem. Leaves opposite, 

 long-petioled ; the basal leaves pinnate ; their segments pinnatifid, with 



