RUBlACE.*i. (madder FAMILY.) 223 



the top. Seeds rather few (4-20 in each cell), peltate and saucer-shaped or 

 globular-thinible-shaped, pitted. — Small herbs, with short entire stipules con- 

 necting the petioles or narrowed bases of the leaves, and cymose or solitary and 

 peduncled flowers. These are dimorphous, in some individuals with exserted 

 anthers and short included style ; in others the anthers included and the style 

 long, the stigmas therefore protruding. (Named for Dr. Wm. Houston, an 

 English botanist who collected in Central America.) 



* Small and delicate, vernal-Jioivering ; peduncles \-Jloicered ; corolla salver- 



form; upper half of the broad and somewhat 2-lohed pod free ; seeds globu- 

 lar, with a veri/ deep round cavity occupying the inner face. 



H- Perennial by delicate Jilif arm creeping rootstocks or creeping steins ; peduncles 



fliform, 1-2' long. 



1. H. eserulea, L. (Bluets. Innocence.) Glabrous ; sfe?«s erec/, slen- 

 der, sparingly branched from the base (3 - 5' high) ; leaves oUong-spatulate (.3 - 

 4" long) ; peduncle filiform, erect ; corolla light blue, pale lilac or nearly wliite 

 with a yellowish eye, with tube much longer than its lobes or than those of the 

 calyx. — Moist and grassy places, N. Eng. to Ga., west to Mich, and Ala. ; pro- 

 ducing from early spring to midsummer its delicate little flowers. 



2. H. serpyllifolia, Michx. Like the last, but filiform stems prostrate, 

 extensively creeping and rooting; leaves orbicular to ovate (2 -4" long); co- 

 rolla rather larger, and deep violet-blue. — Along streamlets and on mountain- 

 tops, Va. to Tenn. and S. C. 



-t- -)- Winter-annuals, branching from the simple root; peduncles much shorter. 



3. H. patens, Ell. An inch to at length a span high, with ascending 

 branches and erect peduncles ; leaves spatulate to ovate ; corolla much smaller 

 than that of n. 1, violet-blue or purplish without yellowish eye, tlie tube longer 

 than its lobes, tivice the length of the calyx-lobes. — Dry or sandy soil, S. Va. to 

 Tex. and 111. (?) 



4. H. minima, Beck. Move dif^nse, commonly scabrous; stems at length 

 much branched and spreading (1-4' high) ; lowest leaves ovate or spatulate, 

 the upper oblong or nearly linear ; eanier peduncles elongated and spreading 

 in fruit, the later ones short; tube of the purplish corolla not longer than its lobes 

 or the ample calyx-lobes (1|" long). — Dry hills. Mo. to Tex. March -May. 



* * Erect, mostly perennial herbs (6-20' high), with stem-leaves sessile, and flow- 



ers in small terminal cymes or clusters ; corolla funnel-form, purplish, often 

 hairy inside ; seeds meniscoidal, with a ridge across the hollowed inner face. 



5. H. purpiirea, L. Pubescent or smooth (8-15' high); leaves vary 

 ing f'om roundish-ovate to lanceolate, 3-5-ribbed ; calyx-lobes longer than the 

 half-free globular pod. — Woodlands, Md. to Ark., and southward. May - July. 

 — Varying wonderfully, as into . — 



Var. ciliolata, Gray. A span high ; leaves only V long, thickish ; cauline 

 oblong-spatulate ; radical oval or oblong, rosulate, hirsute-ciliate ; calyx-lobes 

 a little longer than the pod. — Rocky banks, from the Great Lakes and Minn, 

 to Ky. ; passing into 



Var. longifolia, Gray. A span or two high, mostly glabrous, thinner- 

 leaved ; leaves oblong-lanceolate to linear (6-20" long) ; radical oval or oblong. 



