192 CISTACEAE. 



slightly clasping: cymes few-flowered: sepals oblong to oblong-obovate, 4-5.5 

 mm. long: petals bright-yellow, 7-10 mm. long: capsules globose-ovoid, 4-5 

 mm. long, obtuse. — S. Islands and sandy shore of the Susquehanna. — Schists. 



6. H. prolificum L. Plants shrubby, 3-12 dm. tall, the branches narrowly 2- 

 winged : leaf-blades narrowly oblong or rarely lanceolate, 2-8 cm. long, short- 

 petioled: cymes few-flowered, short-peduncled, in cylindric panicles: sepals 

 mostly obovate, 4-6 mm. long: petals deep-yellow, 8-10 mm. long: capsules 

 conic or narrowly ovoid, 8-10 mm. long, acute. — Susquehanna valley. Fre- 

 quent, on shores and islands. — Shrubby St. John 's-wort. 



7. H. Ascyron L. Plants mostly 1-2 m. tall: leaf -blades ovate-lanceolate to 

 oblong-lanceolate, or narrowly ovate, 3-8 cm. long, obtuse or acutish, clasping: 

 cymes few-flowered: sepals ovate, 7-11 mm. long: petals bright-yellow, 2-2.5 

 cm. long : capsules conic, 2-3 cm. long. — M. S. Islands and shore of the 

 Susquehanna, and along the Little Conestoga. — Limestones, schists. 



3. SAROTHRA L. Partially succulent annual herbs. Sepals 5, equal or 

 nearly so. Stamens grouped. Styles relatively long. Capsule exserted. 



1. S. gentianoides L. Stems 1-5 dm. tall: leaves scale-like, appressed, often 

 subulate or those on the lower part of the stem sometimes linear or narrowly 

 oblong: sepals linear or linear-lanceolate, 2-3 mm. long: corolla yellow, 4-8 

 mm. broad : stamens 5-10 : capsules conic; 4-5 lum. long. — Common, in sandy 

 and gravelly soil. — Sum. — Pineweed. Orange-grass. 



4. TRIADENUM Eaf. Herbs, resembling species of Hypericum. Sepals 

 5, equal. Stamens mostly 9, grouped in 3 's, the filaments of each group well 

 united. Styles relatively long. Capsule exserted. 



1. T. virginicum (L.) Eaf. Stems 2-6 dm. tall: leaf -blades oblong, elliptic, 

 or ovate, 2-10 cm. long, obtuse, clasping: sepals lanceolate to oblong, 5-6 mm. 

 long, acute: petals obovate to oblanceolate or nearly oblong, 8-10 mm. long, 

 acute, delicately nerved : capsules oblong, 8-10 mm. long. — N. S. Eare, in 

 swamps. — Sandstones and shales, schists. — Sum. — Marsh St. John 's-wort. 



Family 2. CISTACEAE. Rock-rose Family. 



Shrubs or partially woody plants. Leaves alternate or opposite: 

 blades simple. Flowers generally perfect. Calyx of 3-5 persistent sepals. 

 Corolla of 5 or 3 often fugaeeous petals, or wanting. Androecium of 6 or 

 more stamens. Gynoecium of usually 3 united carpels. Fruit a capsule. 



Petals 5, vellow, fugaeeous, or wanting : stigmas not fimbriate. 1. Ceocanthemom. 

 Petals 3, not yellow, marcescent-persistent : stigmas fimbriate. 2. Lechea. 



1, CROCANTHEMUM Spach. Erect plants. Leaf -blades linear or wider. 

 Flowers complete and showy, and with many stamens in the early part of the 

 season, inconspicuous and with few stamens later or sometimes all conspicu- 

 ously petaliferous. Ovules pendulous. Capsules of the petaliferous flowers 

 larger than those of the apetalous ones. — Eock-rose. 



1. C. canadense (L.) Britton. Stems 1-6 dm. tall: leaf -blades oblong, linear- 

 oblong, or oblanceolate, nearly sessile, 1.2-3 cm. long, rough and dark-green 

 above, paler and canescent beneath: petaliferous flowers with 30 stamens and 

 30-60 ovules, their corollas 1.8-3 cm. wide^ their capsules ovoid or obovoid and 

 6-8 mm. long: apetalous flowers appearing later, axillary, nearly sessile, with 

 4 stamens and 6-20 ovules, their capsules about 4 mm. in diameter: seeds 

 papillose. — Common, on dry banks and in stony soil. — Spr. and sum. — 

 Frost-weed, 



