388 POLYGONACEAE 



achene l 1 /^ lines in diameter, very much larger than the sepals, entire or 

 emarginate at each end. 



Alpine, among cold wet rocks, 8000 to 12,000 feet: Sierra Nevada, south 

 to Mt. San Jacinto and north to Mt. Shasta. North to the Arctic Circle and 

 around the northern hemisphere. 



Locs. Farewell Gap, Jepson 1019, 1143 ;Mt. Whitney, Jepson 1062; Kearsarge Pinna- 

 cles, Jepson, 856 ; Mt. Goddard, Hall $ Chandler 656 ; Mt. Dana, H. M. Evans ; Conneas Creek, 

 Yosemite Park, Jepson 3362; Castle Peak, Nevada Co., Heller 7097; Mt. Bidwell, Modoc Co., 

 Manning 349. 



Refs. OXYRIA DIGYNA Hill, Hort. Kew. 158 (1768); Merriam, N. Am. Fauna, 16: 144 

 (1899). Eumex digynus L. Sp. PI. 337 (1753), type European. 



4. PTEROSTEGIA F. & M. 



Annuals with very slender and weak stems and opposite leaves. Flowers 

 solitary and nearly sessile in the axils, longer than the subtending bract. 

 Bract rounded and more or less 2-lobed, dentate on the margin, in fruit 

 enlarged, scarious and reticulated, loosely enclosing the achene and develop- 

 ing 2 sac-like protuberances on the back. Calyx 6 (or 5) -parted; stamens as 

 many or fewer than the lobes. One species. (Greek pteron, a wing, and 

 stege, a covering, in reference to the bract.) 



1. P. drymarioides F. & M. Stems commonly several from the base, usu- 

 ally with a branch at each node, diffuse or straggling, a few inches to l 1 /^ 

 feet long; leaves roundish or broader than long and notched once or twice 

 at apex or even cleft, or distinctly fan-shaped or obcordate, 2 to 6 (or 10) lines 

 broad, narrowed at base to a slender but mostly short petiole ; flowers reddish, 

 less than 1 line long; calyx-segments oblong-lanceolate. 



Foothills, under trees in open woods, or in the shade of rock outcroppings, 

 throughout California. North to Oregon, south to Lower California. Apr.- 

 May. 



Locs. Morley's Sta., Shasta Co., Baker $ Nutting; N. Tule River, Purpus 5686; Ar- 

 buckle, Alice King; Conn Valley, Napa Co., Jepson; Santa Maria, Blochman; Canon Diablo, 

 Parish; San Bernardino, Jepson 5527; Santa Monica, Barber 162; San Diego, K. Brandegee. 



Refs. PTEROSTEGIA DRYMARIOIDES F. & M. Ind. Sem. Hort. Petrop. 2: 48 (1835), type loc. 

 Bodega; Jepson, Fl. W. Mid. Cal. 149 (1901). 



5. PHYLLOGONUM Cov. 



Prostrate annual with the leaves basal and in 3s at the nodes. Flowers 

 yellow, pedicelled, borne in close fascicles at the nodes, without involucre or 

 bracts. Calyx deeply cleft into 6 divisions. Stamens 9. One species. (Greek 

 phullon, leaf, and gonu, knee, on account of the leafy, not bracteate, nodes.) 



1. P. luteolum Cov. Stems several from the base, 3 to 5 inches long with 

 3 to 5 branches at the nodes; herbage yellowish, nearly glabrous; leaves 

 obovate, drawn down to a petiole ; calyx % to 1 line long. 



Death Valley region. Collected only by Coville. 



Refs. PHYLLOGONUM LUTEOLUM Cov. Contrib. U. S. Nat. Herb. 4: 190 (1893), type loc. 

 Furnace Creek Canon, Funeral Mts., Coville 584. Eriogonum luteolum Jones, Contrib. 11: 



6. NEMACAULIS Nutt. 



Annual with very slender stems and mostly basal white-woolly leaves. 

 Flowers crowded in subglobose heads ; heads sessile in the forks and along the 

 branches, each flower subtended by an herbaceous bract. Calyx 6-cleft. Stamens 

 3. Achene short-ovoid. One species. (Greek nema, thread, and kaulos, stem, 

 referring to the slender stems.) 



1. N. denudata Nutt. Stems prostrate or ascending, 6 to 14 inches long, 

 glabrate, reddish; leaves spatulate, narrowed to a petiolar base, y 2 to iy 2 

 inches long, mostly basal with usually a few shorter ones in the axils of the 

 lower bracts; bracts oblong, forming a whorl at the nodes; bracts of the 

 flower-clusters obovate, 1 line long, glabrous below, white-woolly above, the 



