112 XYRIDACEAE 
5. ORONTIUM, L. 
Water plant: with elliptic leaves. Flower column (spadix) tall, cylin- 
dric. The sheath (spathe) at first covers the column, then recedes, and 
in many cases falls. 
O. aquaticum, L. (Fig. 2, pl. 9.) Gotpen Crus. Leaves often float- 
ing in water, 3 to 12 in. long, 4 as wide; entire, with veins nearly parallel. 
Swamps and ponds, southeast part of our area and southward. April- 
May. 
6. ACORUS, L. 
Long, aromatic, creeping rootstalks and grass- or flag-like leaves; grow- 
ing in wet places. Flower column appearing to start from the side of a 
bayonet-like leaf. 
A. Calamus, L. (Fig. 3, pl. 9.) Sweer Frac. CaLamus Root. 
Leaves 2 to 6 ft. high, 1 in. or less broad. Flower stem triangular or 
somewhat rounded. Swamps and along streams, common. May-July. 
Order V.—FARINOSAE. Order of the Spiderworts 
A small order including herbaceous plants, mostly aquatic, but 
including the family Commelinaceae, the plants of which are 
found in rich moist soil. Flowers with 3 or 6 stamens and 1 to 3 
ovaries. Petals 3 or rarely 2; sepals 3. Flowers, except Commeli- 
naceae, are nearly or quite regular; the petals and sepals are below 
the ovary. Flowers generally not individually conspicuous, but in 
some families forming heads or spikes, which are quite showy. 
The order is specially characterized by the technical fact that 
the embryo arises at the end of the ovule opposite to the point of 
attachment of the ovule to the ovary. 
Flowers yellow, in chaffy heads . . . . . XYRIDACEAE 
Flowers white or dull lead color in globose heads 
. . » . « ERIOCAULACEAE 
Flowers blue. 
Plants not aquatic . . . . . . COMMELINACEAE 
Aquatic plants . . . . . . . PONTEDERIACEAE 
Famity I.—XYRIDACEAE. YELLOW-rYED Grass FAMILY 
Marsh plants with grass-like tufted leaves and with twisted, 
angular flower stalks, bearing chaffy terminal heads with yellow 
