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. 



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



3. H. ciliolata. 

 Leaf-blades not ciliate. 4. H. longi/olia. 



1. Houstonia coerulea L. Bluets. Innocence. (Man. p. 86r ; I. 

 F. /. S393-) I" open grassy places or on wet rocks, N. S. to Quebec, 

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

 Philadelphia ; Delaware ; Chester ; Lancaster ; York ; Schu\'l- 

 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 Torn Fringed Houstonia. (Man. p. 862 ; 

 I. F. y. 339S.) 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. /. 3399.) In dry open places. Me. and Ont. to Man., 

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

 Berks; Lancaster; Franklin; Huntingdon; Clarion. 



2. CEPHALANTHUS L. 

 1. Cephalanthus occidentalis L. Button-bush. (IMan. p. S63 ; I. 

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

 and Tex. — Pennsylvania : Northampton ; Bucks ; Chester ; Del.^- 

 WARE ; Lancaster; Luzerne; Franklin; Huntingdon; Erie. 



3. MITCHELLA L. 



1. Mitchella repens L. Partridge-berry. Twin-berry. (Man. 

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

 Tex. — Pennsylvania : Monroe ; North.\mpton ; Bucks ; Delaw.are ; 

 Chester; Lancaster; Franklin; Huntingdon; Tioga. 



4. DIODIA L. 

 1. Diodia teres Walt. Rough Button-weed. (Man. p S64 ; I. 

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

 Mex. andSonora. — Pennsylvania : Northampton ; Bucks ; Del.^ware ; 

 Chester ; Lancaster. 



5. GALIUM L. 

 A. Plants annual (except G. veriim and G. Jfollugo). 



Corolla yellow. i. G.vei-uvi. 



Corolla white or greenish white. 



Fruit smooth and glabrous. 2. G. Mollugo. 



Fruit bristly. 3. G. Aparine. 



