BIRTHWORT FAMILY. 
4. Aristolochia tomentosa Sims. 
Woolly Pipe-vine. (Fig. 1284.) 
A. tomentosa Sims, Bot. Mag. p/. 7369. 1811- 
A twining vine, similar to the preceding, 
but the twigs, petioles, leaves and pedun- 
cles persistently tomentose. Leaves sub- 
orbicular or broadly ovate, obtuse or 
rounded at the apex, 3/-6’ broad when 
mature; petioles rather stout, 1/-3’ long. 
peduncles axillary, mostly solitary, slen- 
der, bractless; calyx densely tomentose, 
the tube sharply curved, yellowish green, 
about 134’ long, its throat nearly closed, 
the limb becoming reflexed, wrinkled, 
dark purple, 3-lobed; anthers contiguous 
in pairs beneath the 3 spreading lobes of 
the stigma; capsule oblong-cylindric. 
In woods, Missouri and southern Illinois 
to North Carolina, Alabama and Florida. 
May-June. 
Family rq. POLYGONACEAE Lindl. Nat. eves Ed. Ay itits  “Gusigtey"* 
BUCKWHEAT FAMILY. 
Herbs, twining vines, shrubs or trees, with alternate or sometimes opposite or 
whorled simple mostly entire leaves, jointed stems, and usually sheathing united 
stipules (ocreae). Flowers small, regular, perfect, dioecious, monoecious or 
polygamous, spicate, racemose, corymbose, umbellate or panicled. Petals none. 
Calyx inferior, free from the ovary, 2—6-cleft or 2—-6-parted, the segments or 
sepals more or less imbricated, sometimes petaloid, sometimes developing 
wings in fruit. Stamens 2-9, inserted near the base of the calyx, or in stami- 
nate flowers crowded toward the centre; filaments filiform or subulate, often 
dilated at the base, distinct or united into a ring; anthers 2-celled, the sacs 
longitudinally dehiscent. Pistil solitary; ovary superior, 1-celled; ovule soli- 
tary, orthotropous, erect or pendulous; style 2—3-cleft or 2—3-parted (rarely 
4-parted), sometimes very short; stigmas capitate or tufted, rarely 2-cleft; fruit 
a lenticular 3-angled or rarely 4-angled achene, usually invested by the persist- 
ent calyx; seed shaped like the pericarp; endosperm mealy; cotyledons accum- 
bent or incumbent, flat; embryo straight or curved. 
About 30 genera and Soo species, of wide geographic distribution. 
Flowers subtended by involucres. 
Ocreae present; calyx 2-4-parted; stamens 3 or fewer. 1. Macounastrum. 
Ocreae none; calyx 6-cleft or 6-parted; stamens 9; achene 3-angled. 2. Eriogonum. 
Flowers not involucrate; stamens 4-8. 
Ocreae present; stigmas tufted. 
Calyx 6-parted; style 3-parted; achene 3-angled. 
Calyx 4-parted; style 2-parted; achene lenticular. 
Ocreae present; stigmas capitate. 
Pedicels mostly several together; achene much surpassing the calyx. 5. Fagopyrum. 
Pedicels usually fascicled; achene mostly enclosed by the enlarged calyx x. 6. Polygonum, 
Pedicels solitary; leaves jointed at the base. . Polygonella. 
Ocreae obscure or w anting, stigmas 2-cleft. . Brunnichia. 
1. MACOUNASTRUM Small. 
(Koenicia L. Mant. 35. 1767. Not Konig Adans. 1763. ] 
Low glabrous annual herbs, with fibrous roots, erect or spreading simple or forked stems, 
alternate or opposite entire leaves, funnelform membranous ocreae, and minute perfect ter- 
minal clustered flowers, subtended by a several-leaved involucre. Calyx 2-4-parted (usually 
3-parted), greenish-white, the segments valvate, equal; pedicels short, subtended by trans- 
parent bracts; stamens 2 or 4, alternate with and often protruding between the calyx-seg- 
ments; filaments short, stout; anthers ovoid. Style 2-3-parted; stigmas capitate; achene 
ovoid, 3-angled or lenticular, exceeding the persistent calyx; embryo eccentric, accumbent. 
. Rumex. 
. Oxyria. 
oo 
om 
Two or three species, the following circumboreal, the others of the higher Himalayas. 
* Text contributed by Dr. Joun K. SMALL. 
