796 CISTACEAE 
clustered or paniculate. Sepals 3-5, persistent, when 5 the 2 exterior ones 
smaller and scale-like, the 3 inner convolute. Petals 5 or 3, or sometimes want- 
ing, often fugacious. Stamens 8, hypogynous. Gynoecium 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. Endosperm starchy 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. HUDSONIA. 
Petals 3, not yellow, persistent. 8. LECHEA. 
1. HELIANTHEMUM Pers.! 
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. Apetalous 
flowers with 3-8 short stamens and 6-20, or rarely 3-6 ovules in each ovary, as a rule less 
than one-half the number in the petaliferous flowers. Style obsolete or short: stigma capi- 
tate or 3-lobed. Capsules of the petaliferous larger than those of the apetalous flowers. Em- 
bryo 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 seattered or panicled clusters. 
Flower-clusters scattered or solitary. 
Sepals becoming 6-8 mm. long: lateral nerves of leaves not promi- 
nent beneath. 3. H. arenicola. 
Sepals becoming 4 mm. long: lateral nerves of leaves prominent be- A 
neath. 4.. H. Georgianum. 
Flower-clusters in more or less elongated thyrsoid panicles. 
Sepals of the apetalous flowers fully 2 mm. long at maturity. D 
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, 
clustered, 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 A 
branches. i 9. H. majus. 
1. Helianthemum Caroliniànum 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, oval, oblong er somewhat 
spatulate, 2-5 cm. long, obtuse or apiculate, ciliate, the upper ones manifestly petioled : 
flowers few : pedicels becoming 1-2 cm. long : sepals various, the larger ovate, becoming 1 
14 mm. long, acuminate, involute at the apex, much longer than broad : corolla yellow, 
2.5-3 cm. broad : petals very delicate : capsules subglobose, 7-9 mm. in diameter. 
In pine lands, South Carolina to Florida and Texas. 
2. Helianthemum corymbósum 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 be- 
neath, 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: apetalous 
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 arenícola 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 solitary or 
few 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 
mm. long: corolla yellow, 16-20 mm. broad : capsules oval, about 4 mm. long. 
In shifting sand, along or near the coast, Florida. 
! Revised by Dr. John H. Barnhart. 
