FAMILIES OF PLANTS 
85 
flower consists of a single stamen and a pistillate flower of a single 
pistil. Represented here by Waterstar {Gallitriche palustris). The 
submerged leaves of this plant are linear, or nearly so, while the 
floating leaves are much broader. 
EALSE MERMAID EAMILY (LIMNANTHACEAE) 
Low, weak plants with alternate, pinnate leaves and tiny, incon¬ 
spicuous flowers. Floerkia occidentals and F. proserpinacoides have 
been reported in the park, but they are not common and are of little 
importance. 
SUMAC EAMILY (ANACARDIACEAE) 
The family consists of shrubs and small trees with alternate, com¬ 
pound leaves and small flowers. Usually the fruits are more con¬ 
spicuous than the flowers. Some of the white-fruited species are 
very poisonous to the touch and one should be very cautious about 
handling any shrub whose leaves have three leaflets until one has 
become very familiar with poison-ivy. Whenever one suspects that 
he has been in contact with poison-ivy, he should wash his hands 
and face very thoroughly in strong soapsuds, or better still in a 
solution of ferric chloride, as soon as possible. 
Western poison-ivy {Rhus rydbergii ).—Usually less than 3 feet 
high. The leaves have three rather large leaflets which are somewhat 
toothed but not lobed. The berries are white when matured. The 
whole plant is very poisonous to the touch. It is known to occur 
only for a short distance along the Gardiner River between Mam¬ 
moth and the North Entrance. 
Lemonade sumac {Rhus trilobata ).—This is a much-branched shrub, 
2 to 5 feet high. The leaves have three rather small leaflets, which 
are toothed and somewhat lobed above the middle. The fruits are 
bright red, sticky, and very showy when mature. This plant is 
somewhat ill-smelling, but it is not poisonous to the touch. 
MAPLE EAMILY (ACERACEAE) 
A family of valuable trees and shrubs with opposite leaves and 
sweet sap. The only representative in the park is the Dwarf or Rocky 
Mountain maple {Acer glabrum ), a large shrub or small tree with 
three-lobed and toothed leaves. 
BUCKTHORN EAMILY (RHAMNACEAE) 
A family of shrubs and trees of no very great importance. Repre¬ 
sented in our flora by the Snowbrush {Cecmothus velutinus ), a 
smooth shrub, 2 to 5 feet high, growing in dense clumps or patches. 
