5(4). Trailing glabrous evergreen herbs of dense woodlands; fruit a soft berry- 

 like scarlet drupe 5. Mitchella 



5. Erect to ascending or rarely prostrate nonevergreen herbs mostly in weedy or 



waste areas; fruit capsular, with 2 or more carpels (6) 



6(5). Capsule splitting when ripe into 2 carpels with one carpel open on the 

 inner face, the other one closed 6. Spermacoce 



6. Capsule splitting when ripe into 2 or 3 carpels, if tardily splitting then con- 



spicuously 6-ribbed 7. Diodia 



1. Galium L. Bedstraw. Cleavers 



Slender annual or perennial herbs with 4-angled slender stems and whorled 

 sessile or short-petioled leaves, the roots often containing a red coloring matter; 

 stipules foliaceous; flowers perfect or in some species unisexual, mostly in axillary 

 or terminal cymes or panicles, occasionally solitary or few on simple branchlets, 

 the pedicels usually jointed with the calyx; calyx tube ovoid or globose, the 

 teeth obsolete; corolla rotate, 3- or 4-lobed, valvate in the bud; stamens 4, rarely 

 3, short; styles 2; fruit dry or fleshy, globular or ellipsoid, twin, separating when 

 ripe into the 2 seedlike indehiscent 1 -seeded carpels. 



About 400 species of wide geographic distribution. 



1. Fruit smooth or (at most) granulose (2) 



1. Fruit ornamented with hairs or occasionally verrucose, tuberculate or muric- 



ate (6) 



2(1). Plant glabrous throughout; pedicels short and stoutish; leaves in whorls 

 of 4 (3) 



2. Plant more or less scabrous (on angles of stems and/ or on leaves); pedicels 



elongate and slender; leaves in whorls of 4 to 6 or 8 (4) 



3(2). Leaves firm, with callous margins, mucronate at apex; flowers sessile in a 

 whorl of bracteal leaves; ovary and young fruits scabro-puberulous 

 or at length granulose 1. G. microphyllum. 



3. Leaves fleshy-thickened, without callous margins, obtuse at apex; flowers on 



short pedicels, the bracts fugacious; ovary and fruit smooth 



2. G. Brandegei. 



4(2). Corollas white, 2-3 mm. broad, typically with 4 acute to acutish lobes; 

 stems smooth, stifiish, erect or suberect, without matted basal 

 autumnal offshoots 3. G. obtusum. 



4. Corollas greenish-white, 1.5 mm. broad or less, typically with 3 (sometimes 4) 



obtuse lobes; stems scabrous, diffuse or weakly reclining, developing 

 prostrate matted basal offshoots (5) 



5(4). Leaves linear to linear-oblanceolate, typically in whorls of 4; the filiform 

 simple peduncles or the 2 or 3 filiform arcuate pedicels scabrous, 



5-30 mm. long; distribution New Mexico and Arizona 



4. G. trifidum. 



5. Leaves broadly oblanceolate to oblong-spatulate, those of the main axis in 



whorls of 4, 5 or 6; the stiff'er and straighter peduncles mostly 

 shorter than above, the 2 to 4 pedicels glabrous; distribution 

 Oklahoma and Texas 5. G. tinctorium. 



6(1). Fruits tuberculate or with slender or bristly strongly hooked hairs (7) 



6. Fruits with slender or bristly straight or only slightly curved hairs (8) 



7(6). Plant densely pilose to hirsute throughout; leaves in whorls of 4 



6. G. uncinulatum. 



7. Plant not pilose nor hirsute, at most somewhat scabrous or hispidulous- 



ciliolate; leaves in whorls of 5 to 8, usually 6 



7. G. mexicanum var. asperulum. 



1539 



