MILKWEED FAMILY. 323 



Herbage hoary-tomentose; leaves broad. 



Umbels on peduncles longer than the pedicels. 



Hoods twice as long as the stamen-column; corolla purplish; leaves opposite.... 



2. A. speciosa. 

 Hoods not exceeding the column; corolla creamy-white; some of the leaves in whorls 



of 3 or 4 3. A. eriocarpa. 



Lateral umbels sessile, the terminal one peduncled; hoods not exceeding the column; 



leaves all opposite 4. A. vestita. 



No horns to the hoods of the stamens. 



Hoods conical, open down the front, a little exceeding the anthers; herbage glabrous, 



greenish or purplish 5. A. cordifolia. 



Hoods pointless, lower than the anthers, cleft half-way down the back; herbage white- 

 tomentose 6. A. calif or nica. 



1. A. mexicana Cav. X arrow-leaf Milkweed. Stem slender, about 2 ft. 

 high; herbage glabrous; leaves linear to linear-lanceolate, in whorls of 3 to 6, 

 or the lower and uppermost opposite, 2% to 6 in. long, 2 to 6 lines broad, short - 

 petioled; umbels many, often in whorls or corymbose, densely many-flowered, 

 on peduncles longer than the pedicels; flowers small, greenish white or tinged 

 with purple; corolia-lobes oblong, 2 lines long; horns slender, subulate, exserted 

 from the hood and incurved over the summit of the disk; follicles 3 or 4 in. 

 long, about 4 lines thick at the widest part; seeds 3*4 lines long. 



Forming patches in dry ground, common and widely distributed in barren 

 valley fields: Sacramento and San Joaquin valleys; Coast Ranges but not im- 

 mediately on coast within our limits, or rare; Southern California. July- Sept. 

 Said to poison cattle. 



2. A. speciosa Torr. Creek Milkweed. Stem stout, 2 to 4% ft. high, leafy 

 to the top; soft-tomentose, or rarely glabrate in age; leaves opposite, oval to 

 ovate or oblong, transversely veined, acute or obtuse, 4 to 5% in. long; petioles 

 3 to 5 lines long; peduncle longer than the woolly pedicels; lower umbels with 

 6 to 10 flowers, the upper with 18 or 20 to as many as 55; petals pink or red- 

 dish purple; hoods with a short involute base, above this abruptly contracted 

 into a nearly flat lanceolate portion, the whole fully twice as long as the stamen- 

 column; horns much exserted, incurved over the central disk; follicles soft-spiny, 

 at least toward the apex. 



Dry flats of canon bottoms or along streams: Sacramento Valley and south 

 nearly to Haywards, TV. TV. Carruth; common in the Sierra Nevada and east to 

 the Rocky Mts. May-Aug. More or less poisonous. 



3. A. eriocarpa Benth. Stem 1% to 3 ft. high, more or less sharply angled 

 below; herbage hoary-tomentose, in age more or less deciduous; some of the 

 leaves in whorls of 3 or 4, all broadly oblong with truncate base, rounded or 

 acute at apex, 5 to 7 in. long, short-petioled; umbels few or several, mostly 

 corymbose-clustered toward the summit, on peduncles equaling or rather longer 

 than the pedicels; flowers SYo lines long; corolla creamy-white; hoods with 

 slight purplish tinge, shorter than the anthers, cleft a short distance down the 

 back, the acute sickle-shaped horn Little protruded from between the acute teeth 

 of the cleft. 



Dry ground: Mendocino and Lake cos. and southward through the Coast 

 Ranges to Southern California. Julv-Aug. Said to poison sheep. 



A. eremontii Torr. Similar to no. 3 ; umbels 1 or 2 ; peduncles not longer 

 than the pedicels; hoods nearly erect, equaling the anthers, rather evenly trun- 

 cate; horn broad, its apex subulate, inflexed and a little exserted. — Upper 

 Sacramento westward to Mendocino Co. 



4. A. vestita JI. *!*,- A. Woolly Milkweed. Stem unbranched, 2V_, to 3 ft. 

 high; white-woolly, at length densely floccose; leaves opposite, ovate to oblong- 

 lanceolate, the upper more acuminate and often Bubcordate at base, short- 



