Genus i. 



HEATH FAMILY. 



677 



About 5 species, natives of the north temperate and sub-arctic zones. Besides the following, 

 2 others occur on the Pacific Coast. Types species : Ledum palustre L. 



Leaves linear, i"-i" wide; stamens about 10. i. L. decnmbcns. 



Leaves oblong, 3"-8" wide ; stamens 5-7. 2. L. grocnlandicunt. 



I. Ledum decumbens (Ait.) Lodd. Narrow 

 leaved Labrador Tea. Fig. 3213. 



L. palustre decumbens Ait. Hort. Kew. 2: 65. 1789. 

 L. decumbens Lodd.; Steud. Nomencl. Ed. 2, 20. 1S41. 



A shrub, about 1 high, the twigs rusty-tomentosc. 

 Leaves linear, obtuse, dark green and somewhat rugose 

 above, densely tomentose with brown wool beneath, 

 strongly revolute-margined, i'-i' long, l"-2" wide; 

 flowers 3"-$" broad ; pedicels very pubescent, 4"-8" 

 long in fruit; stamens 10; capsule obovoid or oval, 

 scurfy, about 2" high and ll" in diameter, nodding; 

 calyx-teeth less than i" long, broadly ovate to half- 

 orbicular, obtuse. 



In bogs. Newfoundland to Maine and Quebec, west to 

 Alaska. Also in northern Asia. In our first edition in- 

 cluded in L. palustre L., of Europe and Asia. Summer. 



i:T^'!f 



2. Ledum groenlandicum Ueder. 

 Labrador Tea. Fig. 3214. 



Ledum groenlandicum Oeder, Fl. Dan. pi. 567. 

 1771. 



Ledum latifoliuin Ait. Hort. Kew. 2: 65. 1789. 



A shrub, i-4 high, similar to the pre- 

 ceding species, the twigs densely tomentose. 

 Leaves oblong, obtuse, 1-2' long, 3"-8" wide, 

 green and slightly rugose above, densely brown- 

 tomentose beneath, strongly revolute-mar- 

 gined ; flowers 4"-s" broad, umbellate or short- 

 corymbose; pedicels brown-canescent or tomen- 

 tose, io"-i2" long and recurved in fruit ; 

 stamens 5-7; capsule oblong, canescent, nod- 

 ding, z"-2l" long, i"-ii" in diameter. 



In bogs and swamps, Greenland : Labrador to 

 British Columbia, Massachusetts, eastern Penn- 

 sylvania, Wisconsin, Saskatchewan and Washing- 

 ton. May-Aug. 



2. AZALEA L. Sp. PI. 150. 1753. 



Erect mostly tall branching shrubs, with alternate thin deciduous leaves. Flowers large, 

 white, purple, yellow, pink, or orange, in terminal umbels developed from cone-like scaly 

 buds.' Calyx small or minute, S-parted. Corolla fnnnelform, the tube mostly narrow, the 

 limb nearly regularly s-lobed or somewhat 2-lipped. Stamens 5 (rarely lo), exsertcd, usually 

 declined ; anthers awnless, attached to the filaments by their backs, the cells opening by 

 terminal pores; styles slender, declined, exserted. Ovary 5-celled ; ovules numerous in the 

 cavities. Capsule oblong or linear-oblong, s-celled, septicidally _5-valved^ from the summit, 

 many-seeded. [Greek, dry, from the habitat of one of the original species.] 



About 40 species, natives of North America and Asia. Besides the following, another occurs 

 on the Pacific Coast and 2 or 3 in the Southern States. Type species: Azalea indica L. The ginis 

 is included in Rhododendron by some authors. 

 Flowers expanding before or with the leaves. 

 Flowers pink or white. 



Leaves strigose on the midrib beneath ; corolla-tube hirsute. i. 



Leaves canescent beneath : corolla-tube glandular. 2. 



Flowers orange, yellow or red ; leaves canescent beneath. 3. 



Flowers expanding later than the leaves. 



Leaves shining, glabrous beneath. 4- 



Leaves strigose on the midrib beneath. 5- 



A. nudiflora. 

 A. canesccns. 

 A. lutea. 



A, arboresccns. 

 A. viscosa. 



