462 COMPOSITAE 
3. Tetradymia argyraea Munz & Roos. Striped Horsebrush. Fig. 5807. 
Tetradymia argyraea Munz & Roos, Aliso 2: 237. 1950. 
Much-branched — mostly 6-15 dm. tall; yo twigs densely and step aaat tomentose 
in lines that are sep ted by subgla Aa intervals. ie lesa leaves a cate ntulose and 
i . lo i 
i 
about 1 cm. long or ay ah eho us or cone nies ; heads in small cymos e cluste rs terminating the 
branches ; involucre 6-8 mm. high, of 5 closely and densely tomentose beac: flowers 5 in each 
head; achen es pre ies pappus copious and well developed. 
Dry rocky slopes at about 5, ao ie 6,500 feet, Upper Sonoran and Arid Transition Zones; Kingston. ~ Clark 
a of San Bernardino Cou , Cali fornia. Type bocality: north side of the Kingston Mountains. July— 
4. Tetradymia stenolépis Greene. Mojave Horsebrush. Fig. 5808. 
lepis Greene, Bull. Calif. Acad. 1: 92. 1885. 
uch-branched shrubs, mostly 4-8 dm. tall; young twigs densely and persistently tomentose 
all a enc rarely with more thinly on rat lines Primary leaves mostly modified into stout 
divaricate spines 2-3 cm. long that spread at a ids angle to the twigs, or the lowermost ones 
eola h con 
Tetradymia st 
1 cm. lo ant small c 
involucre 10-12 mm. high, densely and closely tomentose bracts; s each head; 
achenes more or less Saeekceit but the hairs one partly deciduous; pappus sali and well 
developed. 
De ee slopes, saci og — s; Mojave Desert in San Bernardino and Kern nay extending to Los 
Angeles and Inyo Counties, California, ane. ete tuern Lower California. Type cone sg “A short distance south- 
west of the Southern Pacific cara between Cameron and Mohave stations.”” Aug.—Sep 
5. Tetradymia comésa A. Gray. Cotton-thorn. Fig. 5809. 
Tetradymia comosa A. Gray, Proc. Amer. Acad. 12: 60. 1876. 
Much-branched shrubs mostly 6-12 dm. tall with many erect virgate arora Bape 
densely and generally permanently white-tomentose. Ear lier primary leaves soft, linear, 2.5-6 
often 2m i p a 
m 
redeote see ce like the herbage; flowers about in each head; achenes very densely pubes- 
cent with very long, erect, white hairs which equal or exceed and conceal ae scanty ah fragile 
Pappus 
ers — at ey below 5,000 feet, mostly Sonoran Zones; in interior Some ig o myaged ee peony 
less dociunaty m the Mojave Desert, and extending north, on the east side of the Sierra Nevada, as far as Reno, 
Nevada. Type loc ocality: southeastern rig of California; and San Dice ounty, California, gpa 
The typical form of the s s described above, is largely replaced in comers Nevada by a fccen with 
mostly 4 involucral bracts and ‘y toe ar a per vost that has heen ier ge s T. comosa subsp. tetrameres (Blake, 
Proc. Biol. Soc. Wash. 35: 176. 1922). Poe or Sal hare yet definitely She ‘tcoas California, "lente of this nature 
are to be eisectnd near the eastern boundary of the 
6. Tetradymia spinédsa Hook. & Arn. Catclaw Horsebrush. Fig. 5810. 
Tetradymia spinosa Hook. & Arn. Bot. Beechey 360. 1838. 
uch-branched shrubs mostly 5-12 dm. tall; twigs densely, persistently, a. rather rad 
entos i 1 
Be ; 
densely pubescent with very long, erect, white hairs which nearly or quite equal and more or 
less conceal the rather scanty and fragi le p Pappu 
Dry n places in the foothills and plains, mos » he id Transition Zone; southwestern Montana and central 
Tdaho ‘ southeastern Oregon in Harney County — "abethern ee er south to southwestern Colorado, 
southern Utah, Reno, Nevada, and peek County, California. Type : “Snake Country” rex sumably in 
Tda . May a 
adymia spinosa var. longispina M. E. Jones. Proc. Calif. Acad. II. 5: 698. 1895. (Tetradymia aril- 
a he Bot. Gaz. 37: 277. 1904; T. longispina Rydb. Bull. Torrey _ $f: 471. 1916.) ape ir a 
typical T. cag in o pena hs more often straight spines, at least the longer ones generally 1.5 ¢ 
commonly Ion up long). Dry open pares het the foothills and ng occurring in ane Cp pata ged 
in Lake and Stathese Coettice and more common ard and southward through central and western — 
to southern Utah oe reput cols Arizona) and origge rated end of the San Bernar dibo Mountains, Calif 
Type locality: Meadow Valley Wash, southern Nevada. April—July 
118. LEPIDOSPARTUM A. Gray, Proc. Amer. Acad. 19: 50, 1883. 
Heads discoid, the flowers all tubular and perfect, yellow. Involucral bracts charta- 
ceous or partly subherbaceous, eviden i -_ cate in several series. Receptacle small, flat, 
naked. Cercle lobel ec ualing or longer than the throat. Anthers distinctly sagittate. 
tyle-branches fattened: aaa papillate externally, scarcely hairy, without any well- 
defined appendage, the introrsely marginal stigmatic lines extending nearly or quite to: 
