LEGUMINOS^. CXXXI. ASTRAGALUS. 



265 



species, and like it having the petioles permanent, and therefore 

 falls into section Tragacanthacei. 



SERIES III. TRAGACANTHA'CEI (from rpayoc, tragos, a goat, 

 and aKui'Oa, ftkantha, a spine ; in reference to the similarity of 

 the species to A. trogtu&ntha, which is vulgarly called goat's- 

 thurn). D. C. prod. 2, p. 295. Stipulas adnate to the petioles. 

 The petioles are permanent, and at length become hardened 

 spines. 



13. Tragacantha? (see series for derivation). D. C. I. c. 

 Petioles permanent, becoming as hard as spines. Stipulas 

 adnatc to the petioles. 



* Florvers sessile in the axils of the leaves. 



155 A.TRIGONUS (D. C. astr. no. 81.) flowers axillary, sessile, 

 solitary, concealed tinder the stipulas ; legumes trigonal, acumin- 

 ated, hoary from pubescence; leaflets with 6-7 pairs of leaves, 

 which are clothed with hoary wool. ^ . F. Native of Egypt. 

 Flowers yellowish. 



Trigonal-fruited Goat's-Thorn. Shrub ^ to 1 foot. 



156 A. CR^PTOCA'RPUS (D. C. astr. no. 82.) flowers solitary, 

 axillary, latent ; legumes ovate, hairy, 2-seeded ; leaves having 

 4-6 pairs of linear leaflets, which are as well as the stipulas quite 

 glabrous, f; . F. Native of Armenia. Trag. orientalis humil- 

 lima foliis viciae, &c. Tourn. cor. 29. Flowers pale yellow ? 



Hidden-fruited Goat's-Thorn. Shrub 4 foot. 



157 A. BA'RBA Jovis (D. C. astr. no. 83.) flowers solitary, 

 latent ; calyxes 5-parted, very villous ; legumes ovate, glabrous, 

 almost 1 -celled, 1 -2-seeded ; leaves having 3-5 pairs of oblong, 

 acute, hoary-tomentosc leaflets. !j . F. Native of Armenia. 

 Trag. orientalis humfllima arguntea, &c. Tour. cor. 29. Trag- 

 acantha argentea, Mill. Corolla purplish ? 



Jupiter' s-beard Goat's-Thorn. Shrub ^ to ^ foot. 



158 A. MICKOCE'PIIALUS (Willcl. spec. 3. p. 1332.) flowers 

 axillary, sessile, somewhat capitate ; calyxes woolly, 5-cleft ; 

 leaves having 4 pairs of lanceolate, hoary, mucronate leaflets. 



^ . F. Native of Armenia. 



Sutull-headcd Goat's-Thorn. Shrub -| foot. 



159 A. ERIOCAU'LOS (D. C. astr. no. 84.) flowers axillary, 

 solitary, latent ; calyxes usually hardly 5-cleft ; leaves with 4-5 

 pairs of oblong acute leaflets, which are woolly, as well as the 

 stems. t; . F. Native of Armenia. Trag. orientalis foliis 

 incanis caule et ramulis tomentosis, Tourn. cor. 29. Corolla 

 cream-coloured ? Legume unknown. 



Woolly-stemmed Goat's-Thorn. Shrub -^ foot. 



160 A. CAUCA'SICUS (Pall. astr. p. 2. t. 2.) flowers 2-3-to- 

 gether, axillary, sessile ; calyxes 5-cleft, clothed with woolly 

 villi ; legumes 1-celled, 4-seeded ; leaves having 5-7 pairs of 

 oblong-linear leaflets, which are clothed with hoary tomentum. 



Ij . H. Native of Caucasus, on barren rocks. Flowers white 

 (Bieb.), cream-coloured (Pall.). Stipulas when young clothed 

 with white tomentum, but at length becoming glabrous. Bieb. 

 fl. taur. 2. p. 205. Willd. spec. 3. p. 1331. exclusive of the 

 synonyme of Tournefort. 



Caucasian Goat's-Thorn. Fl. June, July. Clt. 1824. Sh. |ft. 



161 A. GU'MMIFER (Labill. journ. phys. 1790. p. 46. with a 

 figure,) flowers 3-5-together, axillary, sessile ; calyxes 5-cleft, 

 and are, as well as the legumes, woolly ; leaves having 4-G pairs 

 of oblong-linear glabrous leaflets. Ij . F. Native of Mount 

 Lebanon. Flowers yellow, rising from the axils of all the leaves, 

 as well as in the preceding species, and therefore they appear in 

 something like a spike. Gum tragacanth flows from this plant, 

 but more sparingly than from A. i-erus. D. C. astr. no. 85. ex- 

 clusive of the synonyme of Tournefort. 



VOL. II. 



Gum-bearing Goat's-Thorn. Fl. June, July. Sh. J to 1 ft. 



162 A. VE'RUS (Oliv. voy. 3. t. 44.) flowers 2-5-together, 

 axillary, sessile ; calyxes tomentose, obtusely 5-toothed : leaves 

 having 8-9 pairs of linear hispid leaflets. (7 . F. Native of the 

 Levant. A. gummifer var. /:>, hispidulus, D. C. astr. no. 85. 

 Young stipulas clothed with silky villi, adult ones glabrous. 

 According to Olivier, a traveller in the Levant, the greater part 

 of the guni-tragacanth which is imported into Europe is obtained 

 from this plant. Tragacauth exudes from it naturally from July 

 to September, either from wounds made in the shrub by animals, 

 or from fissures occasioned by the force of the juice during 

 the great heats of summer. According as the juice is more or 

 less abundant, tragacanth exudes in twisted filaments, which 

 sometimes assume the form of a small worm, elongated, rounded, 

 and compressed, rolled up upon itself or twisted. The finest 

 and purest tragacanth assumes this form. It is almost trans- 

 parent whitish, or of a yellowish white. It also exudes in large 

 tears, which preserve more or less of a vermicular form. This is 

 more of a reddish colour, and more contaminated with impuri- 

 ties. The quantity of tragacanth furnished by Persia is very 

 considerable. Much is consumed in that country in the manu- 

 facture of silk, and the preparation of comfits. It is exported 

 to India, Bagdad, and Bussorah. Russia also gets some by way 

 of Bakou. Tragacanth, though generally called a gum, differs 

 very much from gum Arabic in its properties. It is opaque, 

 white, difficultly pulverizable, unless when thoroughly dried, and 

 the mortar heated, or in frost, and it cannot be said to be pro- 

 perly soluble in water, for it absorbs a large quantity of that 

 fluid, and increases in bulk. It is totally insoluble in alcohol. 

 Its mucilage differs from that of gum-Arabic in being precipi- 

 tated by the superacetate of lead and oxymuriate of tin, and not 

 by silicized potass, or the oxymuriate of iron. In pharmacy tra- 

 gacanth is employed for forming powders into troches, and ren- 

 dering them tough cohesive substances, by beating them with 

 mucilage of tragacanth, and then drying the mass. For elec- 

 tuaries it is improper, as it renders them slimy on keeping. It 

 is also an improper adjunct to active powders, as it swells up 

 on attempting to mix them with water. It is a demulcent, and 

 may answer the purposes of gum-arabic, being better adapted 

 for allaying tickling cough, and sheathing the fauces in catarrhal 

 affection, owing to its great viscidity. 



True Tragacanth or Goat's-Thorn. Shrub to 3 feet. 



163 A. SEII'FERUS (D. C. prod. 2. p. 296.) flowers and leaf- 

 lets unknown, but the last fall very soon off the plant ; there are 

 fascicles of silky bristles, rising from the axils of the spines. ^ 

 F. Native of the Levant. This species is hardly known, but 

 from the habit it is allied to the preceding plant, but it differs 

 from it in having axillary fascicles of bristles. 



Bristle-bearing Goat's-Thorn. Shrub -| foot. 



164 A. ERIA'NTIIUS (Willd. spec. 3. p. 1332.) flowers axil- 

 lary, sessile, aggregate ; calyxes globose, woolly ; leaves with 5 

 pairs of oblong, acute, glabrous leaflets. J? . F. Native of Ar- 

 menia. Petioles yellowish. 



Woolly-flowered Goat's-Thorn. Shrub ^ foot. 



165 A. BREVIFLORUS (D. C. astr. no. 89. t. 31.) flowers axil 

 lary, sessile, somewhat capitate ; calyx 5-cleft, rather longer than 

 the corolla, having woolly, plumose, filiform lobes ; leaves with 

 6-7 pairs of lanceolate villous leaflets. T? . F. Native of Ar- 

 menia. Lodd. bot. cab. 1388. Trag. orientalis foliis angus- 

 tissimis, flore purpurascente, Tourn. cor. 29. A. eriocephalus, 

 Willd. spec. 3. p. 1333. Flowers purple. 



Var. ft, glaber (D. C. 1. c.) leaflets longer and glabrous, T; . 

 F. Native of Persia. Perhaps a distinct species. 



Short-JloneredGoat's-Thorn. Fl. May, Jul. Clt. 1826. Sh.|ft. 



166 A. AU'KEUS (Willd. act. berl. 1794. p. 29. t. 1. f. 3.) 

 flowers axillary, sessile, disposed in globose heads ; calyx 5- 



M m 



