STANDLEY TREES AND SHRUBS OF MEXICO. 833 



on long filiform pedicels; inner sepals ovate-acuminate, 6 to 7 mm. long in 

 anthesis ; petals 8 to 13 mm. long. 



By Grosser this is considered a synonym of H. scoparium (Nutt.) Grosser, 

 but it appears to be fairly distinct from that (California) species in its much 

 larger flowers. 



2. Halimium chiliuahuense (S. Wats.) Grosser in Engl. Pflanzenreich IV. 193: 



45. 1903. 



Helianthemum chihuahuense S. Wats. Proc. Amer. Acad. 23: 268. 18S8. 



Chihuahua and Hidalgo ; type from pine plains at base of the Sierra Madre, 

 Chihuahua. 



Plants suffrutescent at base, 30 cm. high or less; leaves oblong or oblanceo- 

 late-oblong, 1 to 2 cm. long, obtuse or acute, ciliate and pilose; pedicels sub- 

 equal, shorter than the calyx ; inner sepals of the petaliferous flowers in fruit 

 6 mm. long; petals twice as long as the sepals. 



Besides the type collection, the writer has seen only a single specimen, one 

 collected between Somoriel and Las Lajas, Sinaloa. This represents a taller, 

 more strict plant, but does not appear to differ otherwise from the Chihuahua 

 plant. Grosser gives as a synonym " Cistus ciliaris Moc. in sched.," so he must 

 have seen at least one Mexican specimen besides the type, although he cites 

 no other. 



3. Halimium argenteum (Hemsl.) Grosser in Engl. Pflanzenreich IV. 193: 47. 



1903. 



Helianthemum argenteum Hemsl. Diag. PI. Mex. 20. 1879. 



Region of San Luis PotosI, the type locality. 



Plants much branched, suffrutescent, about 10 cm. high; leaves sessile, 

 crowded, acute, 1 to 1.5 mm. wide, densely white-pilosulous ; pedicels 1.5 mm. 

 long or less ; inner sepals of petaliferous flowers 5 mm. long in fruit ; capsule 

 4 mm. long. 



4. Halimium glomeratum (Lag.) Grosser in Engl. Pflanzenreich IV. 193: 47. 



1903. 



Cistus glomeratus Lag. Gen. & Sp. Nov. 16. 1816. 



Trichasterophijllum hyssopifoUum Link, Jahrb. Gewiichsk. 1": 69. 1820. 



Helianthemum glomeratum Lag.; DC. Prodr. 1: 269. 1824. 



Helianthemum astylum Dunal ; DC. Prodr. 1 : 284. 1824. 



Helianthemum obcordattim Dunal ; DC. Prodr. 1 : 284. 1824. 



Taeniostemma micranthum Spach ; Hook. Comp. Bot Mag. 2: 289. 183G. 



Heteromeris mexicana Spach, Hist. Nat. A^eg. Phan. 6: 104. 1838. 



Sonora and Chihuahua to San Luis PotosI, Morelos, and Oaxaca ; types from 

 Acapulco and ZimapAn. Guatemala and Costa Rica. 



Plants suffrutescent, usually 50 cm. high or less, branched above, minutely 

 stellate-tomentulose ; leaves short-petiolate, oblanceolate-oblong or lance-spatu- 

 late, 1 to 3 cm. long; pedicels of petaliferous flowers often 2 to 2.5 cm. long, 

 the flowers sometimes all cleistogamous ; sepals of cleistogamous flowers 1 to 

 1.5 mm. long ; capsules 6 mm. long in the petaliferous and 2 mm. in the cleistoga- 

 mous flowers. " Juanita " (San Luis PotosI, Jalisco, Valley of Mexico). 



A decoction of the plants is used as a remedy for indigestion and diarrhea, 

 and the dried plants are commonly sold in the markets for that purpose. 



This is probably Cistus mexicanus Sess6 & Moc.^ 



5. Halimium exaltatum Rose & Standi., sp. nov. 



Sinaloa and Michoac^n ; type from dry hills above Uruapan, Michoacan, 

 altitude 1,500 meters {Pringle 10409; U. S. Nat. Herb. no. 463505). 



' PI. Nov. Hisp. 87. 1887. 

 7808—23 21 



