290 RUBIACEAE 



1. HOUSTONIA L. 



Peduncles or pedicels solitary or essentially so, terminal or lateral. , 



Plants erect : sepal lanceolate : corolla-tube glabrous within. 



I. H. coerulea. 

 Plants diffusely spreading and creeping : sepals oblong : corolla-tube pubes- 

 cent within. 2. H. serpyllifolia. 

 Peduncles or pedicels in more or less effuse cymes. 



Leaf-blades, especially those of the basal leaves, conspicuously ciliate. 



3. H. ciliolala. 

 I<eaf-blades not ciliate. 4. H. longifolia. 



1. Houstonia coerulea L,. Bluets. Innocence. (Man. p. 861 ; I. 

 F. f. 3393.) In open grassy places or on wet rocks, N. S. to Quebec, 

 Mich., Ga. and Ala. — Pennsylvania : Monroe ; Northampton ; Bucks; 

 Philadelphia ; Delaware ; Chester ; Lancaster ; York ; Schuyl- 

 kill ; Franklin ; Huntingdon ; Clarion ; Cambria. 



2. Houstonia serpyllifolia Michx. Thyme-LEaved Bluets. (Man. 

 p. 861 ; I. F. / 3394-) Mountains of Pa., Va. and W. Va. to S. C. 

 and Tenn. — Pennsylvania : Somerset, Negro Mt. ; FayETTE. 



3. Houstonia ciliolata Torr. Fringed Houstonia. (Man. p. 862 ; 

 I. F. /. 33gS.') On rocks and shores. Me. (?), Ont. to Mich., Pa., W. 

 Va., Ky. and Ark. — Pennsylvania: Allegheny ; Washington. 



4. Houstonia longifolia Gaertn. Long-lEaved Houstonia. (Man. 

 p. 862 ; I. F. f. 3399.) In dry open places. Me. and Out. to Man., 

 Ga. and Mo.— Pennsylvania : Northampton; Bucks; Chester; 

 Berks ; Lancaster ; Franklin ; Huntingdon ; Clarion. 



2. CBPHALANTHUS L. 

 1. Cephalantbus occidentalis L. BuTTOn-bush. (Man. p. 863 ; I. 

 F. _/". 3403.) In swamps and low grounds, N. B. to Ont., Wis., Neb., Fla. 

 and Tex. — Pennsylvania : Northampton ; Bucks ; Chester ; Dela- 

 ware ; Lancaster ; Luzerne ; Franklin ; Huntingdon ; Erie. 



3. MITCHELLA L. 

 1. Mitchella repens L. ParTridgE-bERRY. Twin-bERRy. (Man. 

 p. 863; l.'P. f. 3404.) In woods, N. S. to Fla., Ont., Minn., Ark. and 

 Tex. — Pennsylvania : Monroe ; Northampton ; Bucks ; Delaware ; 

 Chester; Lancaster; Franklin; Huntingdon; Tioga. 



4. DIODIA L. 

 1. Diodia teres Walt. Rough Button- weed. (Man. p 864; I. 

 'P. f. 3406.) In dry or sandy soil. Conn, to Fla., 111., Kans., Tex., N. 

 Mex. and Sonora..— Pennsylvania : Northampton ; Bucks ; Delaware ; 

 Chester ; Lancaster. 



5. GALIUM L. 

 A. Plants annual (except G, vernm and G. Mollugo). 



Corolla yellow. i. G.verum. 



Corolla white or greenish white. 

 Fruit smooth and glabrous. 2. G. Mollvgo. 



Fruit bristly. 3. G. Aparine. 



