FLORA OF THE DISTRICT OF COLUMBIA. 223 



3. KALMIA L. 



Leaves commonly 2-3.5 cm. wide, usually acute, alternate but clustered near the 

 ends of the young twigs; corolla 1.5-2.5 cm. broad, white or pink; ripe pods 5-7 



mm. thick, on erect pedicels 1 # K. latifolia 



Leaves less than 1.8 cm. wide, usually obtuse, in whorls of 3; corolla 7-12 mm. broad," 



magenta-pink; pods 2-4 mm. thick, on recurved pedicels 2. K. angustifolia.' 



1 Kalmia latifolia L. Mountain laurel. 



Woods; common. May-June. Eastern N. Amer. 



A laurel thicket is shown in plate 38; the flowers are shown in plate 39 

 2. Kalmia angustifolia L. Sheep laurel _ 



Swamps, northeastward; infrequent. May-June. Eastern N. Amer. 



4. RHODODENDRON L. 



1. Rhododendron maximum L. Rhododendron. 



Ravines along the upper Potomac; very rare. June-July. Eastern N. Amer. 



5. AZALEA L. 



Flowers pink, or rarely white, opening in late April or early May, before or with the 

 leaves; coarse hairs on the outside of the corolla tube usually without glands; 

 leaves not glaucous beneath; scales of the winter flowering buds usually glabrous 

 outside, the margins ciliate !. A , nudiflora. 



Flowers usually white, sometimes pink, opening in June or late May, after the growth 

 of the leaves; coarse hairs on the outside of the corolla tube always gland-tipped; 

 leaves often glaucous beneath; scales of the winter flowering buds usually with 

 satiny white hairs outside, besides the hairs of the margins 2. A. viscosa* 



1. Azalea nudiflora L. PlNK AZALEA 



Dry woods and fields; common. Apr.-May. Eastern U. S. (Rhododendron 

 nudiflorum Torr.) 



2. Azalea viscosa L. SwAMp AZALEA 



bwamps, northeastward; frequent. May-June. Eastern U. S. (Rhododendron vis- 

 cosum Torr.) 



A very variable species, several forms of which have been named. In A. viscosa 

 glauca (Michx.) A. Gray the leaves are glaucous beneath; in A. viscosa nitida (Pursh) 

 A. Gray they are green on both sides. Both these forms occur in our region. 



6. XOLISMA Raf. 



1. Xolisma ligustrina (L.) Britton. 



Swamp or woods; common. June. Eastern U. S. (Andromeda ligustrina Muhl.; 

 Lyonia ligustrina DC.) 



7. NEOPIERIS Britton. 



1. Neopieris mariana (L.) Britton. Stagger-bush. 



Swamps or dry or moist woods, Rock Creek and eastward; common. May-June. 

 Eastern U. S. (Andromeda mariana L.; Lyonia mariana D. Don.) 



8. EUBOTRYS Nutt. 



1. Eubotrys racemosa (L.) Nutt. Sweetbells. 



Swamps and dry or moist woods; frequent. May-June. Eastern U. S. (Leucothoe 

 racemosa A. Gray.) 



The winter buda are crimson and conspicuous. 



