THALICTRUM 



CC. Frttits long it u d i u ally 

 veined: stigma terminal, 

 minute, not dilated, style 



short 4. glaucum 



AA. Fls. polygamo-diac ions . 



B. Anthers linear, mucronate: 



filaments thread-like 5. purpurascens 



bb. Anthers ovate: obtuse, fila- 

 ments broadened above 0. polygamum 



aaa. Fls. dioecious, with, rare excep- 

 tions. 

 B. Filaments widened above: 



anthers ovate, rather obtuse 7. aquilegifolium 

 bb. Filaments thread-like: an- 

 thers linear, acute or mu- 

 cronate. 

 C. Mature fruits rather firm 

 or thick - u' a I led , not 

 greatly flattened, filled by 

 the seed. 

 D. Sepals green or greenish. 

 E. Blades of leaflets very 



thin 8. dioicum 



EE. Blades of leaflets firm, 



veiny below 9. venulosum 



dd. Sepals purple 10. Delavayi 



CC. Mature fruits less firm, 

 thin - walled, S-edged, 

 either flattened or turgid. 



D. Leaflets rent thin 11. oocidentale 



dd. Leaflets firm. 



E. Pistils 5-ll(rarely 13): 



akenes flattened 12. Fendleri 



ee. Pistils 7-20: akenes 



turgid 13. polycarpum 



1. petaloideum, Linn. Stem round, nearly 1 ft. high 

 almost naked: lvs. 3-5-parted; lfts. smooth, ovate, en 

 tire or 3-lobed: fls. corymbose, perfect; sepals white 

 rotund; filaments pink; anthers yellow: fr. ovate-ob 

 long, striated, sessile. June, July. N. Asia. L.B.C 

 9:891. — Not yet in American trade lists but well worth 

 cultivating. 



2. sparsifldrum, Turcz. Stem erect, sulcate, 2-4 ft. 

 high, branching, usually glabrous: lvs. triternate, up- 

 per ones sessile; lfts. short-stalked, round or ovate, 

 variable in size and shape of base, round-lobed or 

 toothed: fls. in leafy panicles on slender pedicels, per- 

 fect; sepals obovate, whitish, soon reflexed; filaments 

 somewhat widened; anthers very short: akenes short- 

 stalked, obliquely obovate, flattened, dorsal margin 

 straight, 8-10-nerved; styles persistent. N. Asia, 

 through Alaska to Hudson Bay, in mountains to Colo- 

 rado and southern California. 



3. minus, Linn. (T.purpureum, Schang. T. saxdtile, 

 Vill.). Stems round, sulcate, 1-2 ft. high: lfts. variable, 

 acute or obtusely lobed, often glaucous: fls. drooping, 

 in loose panicles, perfect; sepals yellow or greenish: 

 fr. ovate-oblong, sessile, striated. Summer. Eu., Asia, 

 N. Afr. — A polymorphous species in the variation of 

 the leaflets. 



Var. adiantifdlium, Hort. (T. adiantoides, Hort. T. 

 adianthifdlium, Bess.). Lfts. resembling those of Adi- 

 antum fern. — A form much used and admired. 



4. glaucum, Desf. (T. specibsum, Hort.). Stems 

 erect, round, glaucous, 2-5 ft. high: lfts. ovate-orbicu- 

 lar, 3-lobed; lobes deeply toothed: fls. in an erect 

 panicle, perfect; sepals and stamens yellow: fruits 4-6, 

 ovate, striated, sessile. June, July. S. Eu. 



5. purpurascens, Linn. {T. pnrpureum, Hort.). A 

 polymorphous species, allied to T. polygamum: stem 

 3-6 ft. high, branching above, leafy, pubescent or 

 glabrous, sometimes glandular: lfts. larger than in that 

 type: fls. in a long, loose, leafy panicle, polygamo-dioe- 

 cious; filaments narrow; anthers rather long, taper- 

 pointed: akenes slightly stalked, ovoid, glabrous or 

 pubescent, with 6-8 longitudinal wings; style slender, 

 persistent; stigma long and narrow. Canada to Fla., 

 west to the Rockies. June-Aug. 



6. polygamum, Muhl. Tall Meadow Rue. Erect, 

 3-8 or more ft. high, branching and leafy, smooth or 



113 



THALICTRUM 



1791 



pubescent, not glandular: lvs. three to four times ter- 

 nate or terminally pinnate; lfts. oblong to orbicular, 

 bases variable, 3-5 apical lobes: fls. in a long, leafy 

 panicle, polygamo-dioecious ; sepals white; filaments 

 broadened when young; anthers short: akenes ovoid, 

 stipitate, 6-8-winged or ribbed, with stigmas as long, 

 which become curled. July, Aug. Low or wet grounds, 

 Canada to Fla., westward to Ohio. 



7. aquilegifdlium, Linn. Feathered Columbine. 

 Fig. 2493. Stems large, hollow, 1-3 ft. high, glaucous: 

 lvs. once or twice 3-5-parted ; lfts. stalked or the lateral 

 ones nearly sessile, slightly lobed or obtusely toothed, 

 smooth, suborbicular: fls. in a corymbose panicle, 

 dioecious; sepals white; stamens purple or white: fr. 

 3-angled, winged at the angles. May-July. Eu., N. 

 Asia. B.M. 1818; 2025 (as var. formosum). Gn. 47, p. 

 357; 50, p. 117. — The old name T. Cornuti, Linn., may be a 

 synonym of this, and if so it is the older name, being pub- 

 lished on a preceding page, but T. Cornuti was described 

 as an American plant, while T. aquilegifolium is not. As 

 the description and old figure of T. Cornuti do not 

 agree with any American plant, the name may well be 

 dropped. Those plants advertised as T. Cornuti are 

 probably T. aquilegifolium or T. polygamum. 



8. didicum, Linn. Rather slender, 1-2 ft. high, gla- 

 brous: lvs. three to four times 3-parted; lfts. thin, 

 orbicular, several-lobed or revolute, bases variable : 

 fls. in a loose, leafy panicle with slender pedicels, di- 

 oecious; stamens much longer than the greenish sepals; 

 anthers linear, obtuse, exceeding their filaments in 

 length: akenes ovoid, nearly or quite sessile, longer 

 than their styles, with about 10 longitudinal grooves. 

 Early spring. Woods, Labrador to Ala., west to the 

 foot of the Rockies. 



9. venulosum, Trelease. Allied to T. dioicum: stem 

 simple, erect, 10-20 in. high, glabrous, glaucous, bear- 

 ing 2-3 long-petioled lvs. above the base : lvs. three to 

 four times 3-parted; lfts. short-stalked, rather firm, 

 rounded and lobed at the apex, veiny beneath: fls. in a 

 simple panicle, dioecious, small; sepals ovate; stamens 

 10-20, on slender filaments; anthers oblong, slender- 

 pointed : akenes nearly sessile, 2 lines long, ovoid 

 tapering to a straight beak, thick-walled and 2-edged. 

 S. Dak. westward and southward in the mountains. 





F 



2493. Thalictrum aquilegifolium (X K). 



10. Delavayi, Franchet. Slender, 2-3 ft. high, gla- 

 brous: lower lvs. on long, slender petioles, two to three 

 times 3-5-parted ; lfts. long-stalked, 3-5-lobed, base 

 cuneate, rounded or cordate: fls. pendulous, dioecious; 

 sepals purple or lilac, % in. long, equaling the slender 

 stamens, anthers linear: carpels 10-12: fr. winged at 



