Aceraceae 249 

ACERACEAE Maple Family 
eo Shrubs or trees; sap watery, often sweet. Leaves opposite, simple or 3-foliolate, 
palmately lobed or rarely entire (not ours), or rarely pinnate. Flowers polygamous or 
| dioicous, regular, cymose or racemose, axillary or terminal. Calyx usually 5-parted. 
Petals none or 5. Disk thick, ring-like, lobed, sometimes almost none. Stamens Siz 
often 8. Ovary 2-lobed, 2-celled: styles 2, between the lobes. Fruit composed of 2 
carpels or rarely 3 or 4; carpels united at base, winged, indehiscent. Seeds | or rarely 
2 in each carpels, flattish. 


ACER MAPLE 
Flowers small. Calyx colored. Carpels l-ovuled. (Celtic ac—hard or sharp, 
hence L. acer=these plants, since their hard wood was prized for making weapons.) 
A. Leaves simple or 3-foliolate; disk present. 
Eeteaves: 7——9-lobed, .7.5—13 cm. wide: flowers in corymbs; fruit glabrous; ma- 
ture carpels spreading at about 180°, 2—3.2 cm. long. W. C. E. 
A, circinatum Pursh (Vine Maple) 
BB. Leaves 5—7-lobed, 15-37 cm. wide; flowers in racemes; fruit hispid; mature 
carpels spreading at about 90° or less, 3.75 cm. long. W.C. E. 
A. macrophyllum Pursh (Large-leaved Maple) 
BBB. Leaves 3—5-lobed or 3-foliolate, 2.5—7.5 cm. wide; flowers in corymbs; 
fruit glabrous; mature carpels spreading at about 90° or less, 2-3 cm. long. W. 
Cr FE: (A. douglasit.) A. glabrum Torr. (Rocky Mountain Maple) 
AA. Leaves 3—9-foliolate; disk none. W. E. (Negundo aceroides.) 
Ae negundo L. (Box Elder) : 
BALSAMINACEAE Touch-me-not Family 
Herbs (ours) or undershrubs, succulent (ours). Leaves alternate, thin, simple, den- 
tate, petioled. Flowers somewhat clustered, axillary, showy, very irregular. Sepals ap- 
parently 4, the | notched at apex is probably 2 combined: rear one large, petal-like, sac- 
cate, often spurred. Petals 2—5. Stamens 5, short; filaments with scales on inner 
side, somewhat united; anthers somewhat united. Ovary oblong, 5-celled; style very short 
or none; stigma 5-toothed or -lobed; cells several-ovuled. Fruit (in ours) a capsule, 
oblong or linear, dehiscent into 5 spirally coiled valved. Seed oblong, ridged. 
IMPATIENS TOUCH-ME-NOT 
: Annual and glabrous (ours). Stems somewhat transparent. Petals 4, apparently 
only 2 by the union of the lateral with the adjacent lower ones. Cells of the ovary 
formed by the membranous projections of the placentae which occupy the axis of the 
ovary and are connected with its apex by 5 slender threads. Capsule often |-celled by 
the disappearance of the partitions. (Impatient in that the ripe capsule flies into pieces 
when touched. ) 
A. Posterior sepal spurred. Corolla often spotted. 
B. Spurred sepals slightly longer than wide; sac at least 2/3 as wide as long, abruptly 
contracted into a spur; corolla with large spots or rarely unspotted. E. (J. fulva; 
Ls auriella. ) I, biflora Walt. (Spotted Touch-me-not) 
BB. Spurred sepal much longer than wide; sac not over 1/7 as long as wide, grad- 
_ ually tapering into a spur; corolla unspotted. W.C. (J. occidentalis; [. pallida 
for our region. ) I. nolitangere L. (Garden Touch-me-not) 
AA. Posterior sepal unspurred, wider than long; corolla pale yellow, unspotted. E. 
I. ecalearata Blank. (Spurless Touch-me-not) 

