796 CISTACEAE 



mose, clustered or panieulate. Sepals 3-5, persistent, when 5 the two exterior 

 ones smaller and scale-like, the 3 inner convolute. Petals 5 or 3, or sometimes 

 wanting, often fugacious. Stamens 8, hypogynous. Gynoeeium of several united 

 carpels. Ovary sessile, 1-several-celled. Ovules orthotropous, stalked. Styles 

 united. Stigma entire or 3-lobed. Capsule dehiscent by valves. Seeds several 

 or numerous. Embryo slender, straight or curved. Endospenn sfai'chy or 

 fleshy. 



Petals 5, yellow, fugacious or wanting. 



Styles obsolete or relatively short: leaves with flat or merely revolute blades. 1. Helianthemum. 



Styles slender, elongated: leaves scale-like, .sometimes subulate. 2. Hudsoxia. 



Petals 3, not yellow, persistent. 3. Lechea. 



1. HELIANTHEMUM Pers.i 

 Woody herbs or low shrubby plants. Leaves with flat or revolute blades. Flowers 

 complete or some species with both petaliferous and apetalous ones, the petaliferous often 

 showy, with 12-30 long stamens and 20^60 or rarely 8-10 ovules in each ovary. Apet- 

 alous flowers with 3-8 short stamens and 6-20, or rare]y 3-6 ovules in each ovary, as a 

 ru'e less than one-half the number in the petaliferous flowers. Style obsolete or short : 

 stigma capitate or 3-lobed. Capsules of the petaliferous la,rger than those of the 

 apetalous flowers. Embryo curved. The plants flower in the spring or in the spring 

 and summer. Frost-weed. 



Flowers all alike and petaliferous. 1. H. Carolinianum. 



Flowers of two kinds, some petaliferous others apetalous. 

 Petaliferous and apetalous flowers in the same clusters. 



Flowers in a dense terminal cyme. 2. H. corymbosum. 



Flowers in scattered or panicled clusters. 

 Flower-clusters scattered or solitary. 



Sepals becoming 6-S mm. long: lateral nerves of leaves not promi- 

 nent beneath. 3. H. arenicola. 

 Sepals becoming 4 mm. long: lateral nerves of leaves prominent be- 

 neath. 4. H. Georgianum. 

 Flower-clusters in more or less elongated thyrsoid panicles. 



Sepals of the apetalous flowers fully 2 mm. long at maturity. 



Sepals canescent-puberulent. 5. H. Nashii. 



Sepals hirsute. 6. H. thyrsoideum. 



Sepals of the apetalous flowers less than 2 mm. long. 7. H. rosmarinifolium 



Petaliferous flowers solitary or few, vernal; apetalous flowers numerous, clus- 

 tered, autumnal. 

 Petaliferous flowers 1 or 2, their capsules far overtopped by the apetalous 



inflorescence. 8. H. Canadense. 



Petaliferous flowers 5-12, the apetalous inflorescence on short lateral 



branches. 9. //. majus. 



1. Helianthemum Carolinianum Michx. Stems villous-hirsute or hirsute, erect or 

 ascending, 1-3 dm. tall, often branched at the base, thence simple, or corymbose above : 

 leaves few, often mostly at the base of the stem; blades obovate, ova'l, oblong or some- 

 what spatulate, 2-5 cm. long, obtuse or apieulate, ciliate, the upper ones manifestly peti- 

 oled: flowers few: pedicels becoming 1-2 cm. long: sepals various, the larger ovate, be- 

 coming 12-14 mm. long, acuminate, involute at the apex, much longer than broad: 

 corolla yellow, 2.5-3 cm. broad: petals very de'licate: capsules subglobose, 7-9 mm. in 

 diameter. 



In pine lands. South Carolina to Florida and Texas. 



2. Helianthemum corymbosum Michx. Stems finely and densely canescent, erect, 

 branching from the base, 1.5-3 dm. high: leaf -blades oblong, or the lowest obovate, 2- 

 2.5 cm. long, obtuse or acutish, 6-10 mm. wide, entire, slightly revolute in drying, pale 

 beneath, dark green above, short -petioled: flowers in a nearly naked terminal, fastigiate 

 cyme, the petaliferous with 25-30 stamens and 20 ovules, the apetalous with 3-6 

 stamens and 9 ovules: corolla 16-20 mm. broad: pedicels slender, 6-16 mm. long: apet- 

 alous flowers nearly sessile : calyx of both kinds woolly-pubescent : outer sepals about 

 equalling the inner: capsules of the larger flowers 4-6 mm. broad, many-seeded, those 

 of the apetalous ones smaller and few-seeded. 



In sandy soil, Virginia and North Carolina to Florida and Louisiana. 



3. Helianthemum arenicola Chapm. Stems canescent-tomentulose, several from 

 the woody base, erect or spreading, 1-2 dm. long, often branched above: leaf-blades 

 linear-oblong, 1-2.5 cm. long, obtuse, only the midrib prominent beneath: flowers soli- 

 tary or feAv in terminal clusters, the petaliferous with 25 stamens and 20 ovules, the 

 apetalous with 5 stamens and 10 ovules: sepals various, the larger ovate or oval-ovate, 

 becoming 6-8 mm. long: corolla yellow, 16-20 mm. broad: capsules oval, about 4 mm, 

 long. 



In .shifting sand, along or near the coast, Florida. 



1 Revised by Dr. John H. Barnhart. 



