864 FLORA. 



straight. [Greek, thoroughfare, where the species ire frequently found.] About 

 35 species, mostly American. Besides the following, another occurs in the South- 

 ern States. 



Leaves linear-lanceolate; style entire; stigmas capitate. I. D. teres. 



Leaves lanceolate or oval; style 2-cleft; stigmas filiform. 2. £>. Virginiana. 



1. Diodia teres Walt. Rough Button-weed. (I. F. f. 3406.) Rigid, 

 usually rough, much branched from near the base, the branches prostrate or ascend- 

 ing, 4-sided above, 1-7.5 dm. l° n g- Leaves linear or linear-lanceolate, very rough, 

 1-4 cm. long, acute, the margins revolute when dry; flowers lilac or purple, 

 4-6 mm. long, usually solitary in the axils; style entire; stigmas capitate; fruit 

 obovoid or top-shaped, hispid, about 4 mm. high, the usually 4 persistent calyx- 

 lobes ovate to lanceolate. In dry or sandy soil, Conn, to Fla., 111., Kans., Tex., 

 N. Mex. and Sonora. July-Sept. 



2. Diodia Virginiana L. Larger Button-weed. (I. F. f. 3407.) Hispid- 

 pubescent or glabrate, much branched from near the base, the branches procum- 

 bent or ascending, 3-6 dm. long. Leaves lanceolate to narrowly oval, narrowed at 

 the base, acute, or the lowest obtuse, 2-8 cm. long; flowers I or 2 in each axil, 

 about 12 mm. long, the corolla-tube very slender; fruit somewhat fleshy, but becom- 

 ing dry, hirsute or glabrous, oval, 6-8 mm. high, furrowed, crowned with the 2 

 or 3 persistent lanceolate calyx-lobes. In moist soil, southern N. J. to Fla., Ark. 

 and Tex. June-Aug. 



7. GALIUM L. (See Appendix.) 



Herbs, with 4-angled slender stems and branches, apparently verticillate 

 leaves, and small flowers, mostly in axillary or terminal cymes or panicles, the 

 pedicels usually jointed with the calyx. Flowers perfect, or in some species dice- 

 cious. Calyx-tube ovoid or globose, the limb minutely toothed, or none. Corolla 

 rotate, 4-lobed (rarely 3-lobed). Stamens 4, rarely 3; filaments short; anthers 

 exserted. Ovary 2-celled; ovules one in each cavity. Styles 2, short; stigmas 

 capitate. Fruit didymous, separating into 2 indehiscent carpels, or sometimes only 

 1 of the carpels maturing. Seed convex on the back, concave on the face, of 

 spherical and hollow; endosperm horny; embryo curved; cotyledons foliaceous, 

 [Greek, milk, from the use of G. verwn for curdling.] About 225 species, of wid' 

 distribution. Besides the following, about 27 others occur in southern and westeri 

 N. Am. The leaves are really opposite, the intervening members of the verticil! 

 being stipules. 



* Fruit dry, smooth, hispid, or roughened, 

 f Annuals (except Nos. 1 and 2). 



1. Flowers yellow ; leaves narrowly linear. 1. G. verum. 



2. Flowers white or greenish white. 



a. Fruit smooth and glabrous. 2. G. Mollugo. 



b. Fruit bristly, tubercled. granular or papillose (or smooth in No. 3). 

 Flowers in axillary cymules, or panicled. 



Fruit granular or tubercled, not bristly. 



Fruit slightly granular, or smooth, 1 mm. broad; pedicels not recurved; stem 



very slender. 3. G. Parisiense. 



Fruit granular-tubercled, 3 mm. broad ; fruiting pedicels recurved ; stem stout. 



4. G. tricorne. 

 Fruit densely bristly-hispid. 



Cymes few-flowered ; leaves 2-8 cm. long; fruit fully 4 mm. broad. 



5. G. A par in e. 

 Cymes mostly several-flowered; leaves 1-2.5 cm. long; fruit smaller. 



6. G. Vaillantii. 

 Flowers solitary in the axils, subtended by 2 foliaceous bracts ; fruit bristly. 



7. G. virgatum. 



ft Perennials. 

 1. Fruit bristly-hispid (or becoming glabrous in No. 12). 



a. Leaves in 4's, i-nerved. 8. G. pilosum. 



b. Leaves in 4's, 3-nerved. 

 Leaves lanceolate, oval, or ovate; flowers in open cymes. 



Upper leaves lanceolate to ovate-lanceolate, acuminate. 9. G lanceolatum. 



