Vor. II.] CARROT FAMILY. 513 
5. OXYPOLIS Raf. Neogen. 2. 1825. 
(TrEDEMANNIA DC. Mem. Omb, 51. 1829. ] 
[ARCHEMORA DC. Mem. Omb. 52. 1829. ] 
Erect perennial glabrous marsh herbs, from clustered tuberous roots, with pinnate or 
ternate leaves, or in one species the leaves reduced to hollow jointed phyllodia, and com- 
pound umbels of white flowers. Involucre none, or of a few linear bracts. Involucels of 
several small bracts, or none. Calyx-teeth acute. Stylopodium thick, conic. Fruit gla- 
brous, dorsally compressed, oval or obovate; dorsal and intermediate ribs slender, the lateral 
ones winged, strongly nerved along the inner margin of the wing, the carpels appearing as 
if equally 5-ribbed. Oil-tubes solitary in the intervals, 2-6 on the commissural side. Seed- 
face nearly flat. 
Four known species, natives of North America. 
Leaves all reduced to hollow usually jointed phyllodia. I 
Leaves pinnate; leaflets linear or lanceolate. 2. 
1. Oxypolis filiformis (Walt.) Britton. 
Oxypolis. (Fig. 2639.) 
OEnanthe filiformis Walt. Fl. Car. 113. 1788. 
OEnanthe teretifolia Muh. Cat. 31. 1813. 
Tiedemannia teretifolia DC. Mem. Omb. 51. pi. 12. 1829. 
Oxypolts filiformis Britton, Mem. Torr. Club, 5: 239. 1894. 
Stem hollow, 2°-6° high. Leaves reduced to linear 
hollow usually jointed acute phyllodia 1/-18’ long; in- 
volucre of several linear-subulate bracts; umbels 2/-4’ 
broad, 6-15-rayed; rays slender, 14/-2’ long; pedicels 
2/’-4’’ long; fruit oval, or slightly obovate, 2//-3// 
long; oil-tubes large, 1 in each interval, 2-4 on the 
commissural side. 
In ponds and swamps, southern Virginia to Florida, 
west to Louisiana. Aug.-Sept. Plants collected in Dela- 
ware, referred to this species, differin having broadly oval 
ecorky-winged fruit, an inconspicuous disk, slender conic 
stylopodium and smaller oil-tubes. They may represent a 
different genus. 
. rigida. 
f= 
2. Oxypolis rigidus (1.) Britton. Cow- 
bane. Hemlock, or Water Drop- 
wort. (Fig. 2640.) 
Stum rigidum I,. Sp. Pl. 25%. 1753. 
Archemora rigida DC. Mem. Omb. 52. 1829. 
T. rigida Coult. & Rose, Bot. Gaz. 12:74. 1887. 
O. rigidus Britton, Mem. Torr. Club, 5: 239. 1894. 
Rather slender, 2°-6° high. Leaves petioled, 
simply pinnate, the lower often 1° long or 
more, the uppermost much reduced; leaflets 
thick, ovate-lanceolate, lanceolate or oblong, en- 
tire, or remotely dentate, 114/-3/ long, 3/’-12/” 
wide; involucre of 1-4 bracts, or none; umbels 
2/-4’ broad, 7-25-rayed; rays slender, 1/-4’ long; 
pedicels 2//-9’ long; fruit oval, 214’’-3/” long, 
1%4//-2/’ broad; oil-tubes small, 1 in each in- 
terval, 4-6 on the commissural side. 
In swamps, New York to Florida, west to Wis- 
consin, Minnesota, Missouri and Louisiana. Very variable in leaf-formand size of fruit. Aug.—Sept. 
Oxypolis rigidus longifdlius (Pursh) Britton, Mem. Torr. Club, 5: 239. 1894. 
. Stum longifolium Pursh, Fl. Am. Sept. 194. 1814. 
OE nanthe ambigua Nutt. Gen. 1: 189. 1818. : : 
Leaflets elongated-linear, entire, 1'’-114'' wide; fruit smaller. New Jersey to South Carolina and 
Tennessee. x 
6. HERACLEUM L. Sp. Pl. 249. 1753. 
Erect, usually pubescent perennial herbs, with ternately compound leaves, and com- 
pound umbels of white flowers. Bracts of the involucre few and deciduous, or none. In- 
volucels of numerous linear bracts. Calyx-teeth obsolete or small. Petals cuneate, or 
clawed, those of the outer flowers dilated and obcordate or 2-lobed. Stylopodium thick, 
conic. Fruit much flattened dorsally, broadly oval, obovate, or orbicular; dorsal and inter-" 
mediate ribs filiform, the lateral ones broadly winged and the wings nerved near the outer 
margin; oil-tubes extending only to about the middle of the carpels, conspicuous, 1 in each 
interval, 2-4 on the commissural side. [Greek, to Hercules. ] 
About 60 species, natives of the northern hemisphere, only the following in North America. 
33 
