FLOWERING PLANTS AXD FERNS OF ARIZONA 849 



1. Mitracarpus breviflorus A. Gray, PL Wright. 2: 68. 1853. 



Cochise, Santa Cruz, and Pima Counties, 4,000 to 6,000 feet, dry 

 plains and mesas, August and September. Southern Texas, southern 

 Arizona, and Mexico. 



9. GALIUM. Bedstraw 



Plants annual or perennial, herbaceous or suffrutescent; stems 

 angled, often winged, usually weak and reclining or supported on other 

 plants; herbage often retrorsely hispid; leaves appearing whorled, 

 usually narrow; flowers small, perfect or unisexual, in axillary or 

 terminal cymes or glomerules, these often panicled, or the flowers 

 solitary in the axils; fruits didymous (paired), smooth, tuberculate, or 

 covered with straight hairs or hooked bristles, indehiscent; seeds with 

 a deeply concave face. 



The plants have been used as remedies for various diseases, but their 

 medicinal value is questionable. 



Key to the species 



1. Flowers involucrate (closely subtended by leaflike bracts), sessile or nearly so, 

 solitary in each involucre; fruit slightly fleshy at maturity, granulate or 

 tuberculate, not hairy; plant glabrous or nearly so; stems deeply grooved, 

 with thick, whitish angles; leaves apparently 4 in the whorl, the blades 

 somewhat rigid, thickish, shiny, mostly narrowly linear, sharply cuspidate, 



the midrib and margin thick, whitish 1. G. microphyllum. 



1. Flowers not involucrate, usually distinctly pedicellate; fruit not fleshy at 



maturity (2). 



2. Fruit not long-hairy; plants perennial; stems herbaceous above ground (3). 



3. Stems stout, very rough to the touch; leaves apparently 5 or more in the 



whorl, the lower ones commonly more than 15 mm. long, with narrowly 



elliptic, lanceolate, or oblanceolate blades; pedicels less than 5 nun. 



long; fruit tuberculate or minutely hispidulous__ 2. G. asperrimum. 



3. Stems slender, not or barely rough to the touch ; leaves commonly appearing 



to be 4 in the whorl, less than 15 mm. long; pedicels (some of them) 



usually more than 5 mm. long; fruit smooth, glabrate (4). 



4. Herbage glabrous or very nearly so; stems commonly less than 20 cm. 



long, matted 3. G. braxdegei. 



4. Herbage sparsely and minutely hispidulous (exceptionally glabrous) ; 

 stems commonly more than 20 cm. long, not forming mats. 



4. G. TRIFIDUM. 

 2. Fruit conspicuously hairy (sometimes glabrate at maturity in G. boreah , 

 the hairs usually nearly as long as to longer than the transverse diameter 

 of the carpel (5). 

 5. Hairs of the fruit straight, soft, white; plants perennial, more or less woody 

 at base; leaves apparently in whorls of 4, or fewer (6). 

 6. Corolla purplish to dark brown purple; flowers not dioecious; plants 

 suffrutescent; leaf blades linear, narrowly lanceolate, or somewhat 

 oblanceolate (7). 

 7. Steins and leaves hirtellous, at least near the base of the plant; 

 leaves often somewhat flaccid 5. G. wrightii. 



7. Stems and leaves glabrous or puberulent; leaves rigid. 



6. G. ROTHROCKII. 



6. Corolla white, vellowish, or greenish (rarelv purplish): flowers dioecious 

 (8). 



8. Leaf blades obtuse or acutish at apex, thin, not rigid, linear or narrowly 



lanceolate, often reflexed, the midrib slender, not very prominent, 

 the lateral veins obsolete; plant scarcely woody above ground, 

 hirteUous-puberulent to nearly glabrous, scarcely rough to the 



tOUCh_ 7. G. FEXDLEUI. 



