PENTAS 



PENTSTEMON 



2539 



white fls. G.W. 10, p. 611. Var. Quartiniana, Hort. 

 (P. Quartiniana, Oliver) is a rosy-fld. variety said to be 

 much better than the type. Gt. 45, p. 464. 



WlLHELM MlI^LER. 



L. H. B.f 



PENTLANDIA: Urceolina. 



PENTSTEMON (Greek for five stamens, all five 

 stamens being present, whereas related genera have 

 only four; but in Pentstemon one of the stamens is 

 sterile). Sometimes written Pentastemon. Scrophu- 

 lariacese. PEXTSTEMON. BEARD-TONGUE. Tubular- 

 flowered bedding and border plants, mostly of bright 

 colors; many are natives in the United States. 



Perennial herbs or shrubs of medium or small size, 

 spring- and summer-blooming, glabrous or pubescent, the 

 sts. mostly little branched : Ivs. opposite or whorled, entire 

 or toothed (the upper ones sometimes alternate): fls. 

 in terminal racemes or thyrsoid clusters, mostly showy, 

 blue, red, purple, white ; calyx 5-parted, with imbricated 

 segms. : corolla tubular, usually dilated at the throat, 

 distinctly or obscurely 2-lipped, the upper lip 2-lobed or 

 notched and the lower 3-lobed; fertile stamens 4, 

 didynamous, the fifth sterile and sometimes bearded, 

 all of them included or not exserted; style filiform and 

 stigma capitate: fr. an ovoid, globose or oblong dehis- 

 cent caps., with numerous seeds. Pentstemon is a 

 typical American genus. One species is native to N. 

 E. Asia and many to the copier parts of Mex., but the 

 larger number of the species inhabit the U. S. and 

 Canada, particularly the western parts. Krautter 

 admits 148 species in his monograph in 1908 (Contr. 

 Bot. Lab., Univ. of Pa, III). They are all herbs, 

 although some species are somewhat woody at the 

 base. It is difficult so to arrange the species of Pents- 

 temon as to make them easy of determination by the 

 horticulturist. Gray's account in the Synoptical Flora 

 (Vol. 2, Part 1) describes the American species north of 

 Mex. ; and this account has been followed here in the 

 main. The arrangement of species, however, has been 

 modified considerably to admit the Mexican species 

 and to make the group easier for the beginner. Later 

 writers are inclined to raise the Grayan varieties to 

 the rank of species. 



For the hardy border, pents- 

 temons are most satisfactory 

 plants, and the great number of 

 showy species allows much lati- 

 tude in choice of color and habit. 

 All are perennial, but some of 

 them bloom the first year from 

 seed. In a dry and hot place they 

 are likely to be short-lived, 

 although nearly all the species 

 thrive best in full exposure to 

 sun. They should have good deep 

 garden soil. They are propagated 

 by division and by seed, the latter 

 usually being preferred. Many of 

 the species are not hardy in the 

 northern states, but P. barbaius 

 and its varieties, P. hirsutus, P. 

 Isevigatus and variety, P. confer- 

 tus and variety, P. diffusus, P. 

 ovalus, P. grandiflorus, P. acuminatus, P. angustifolius, P. 

 glaber and varieties, and also others, may be expected 

 to stand in the North, particularly if given a protection 

 of leaves. An excellent garden race has been produced, 

 here designated as P. gloxinioides. This seems to be a 

 product of hybridization and selection. It is little 

 known in American gardens, although it is a handsome 

 and deserving plant. Some of the forms of it are 

 treated as annuals. Most of the species described in 

 this account are not domesticated or modified plants, 

 but are sold or distributed as stock secured more or 

 less directly from the wild. 



acuminatus, 21. 

 alpinus, 15. 

 angustifolius, 22, 26. 

 antirrhinoides, 5. 

 argutus, 41. 

 arizonicus, 16. 

 atropurpureus, 26. 

 azureus, 46. 

 barbatus, 7, 8. 

 Bridgesii, 48. 



INDEX. 



Douglasii, 1. 

 Eatonii, 9. 

 erianthera, 36. 

 Fendleri, 21. 

 fruticosus, 1. 

 gentianoides, 12. 

 glaber, 15. 

 glandulosus, 39. 

 gloxinioides, 13. 

 Gordonii, 15. 



csBruleo-purpureu8,24. gracilentus, 43. 



cxruleus, 22. 



campanulatus, 26. 



centranthifolius, 14. 



Clevelandii, 32. 



Cobsea, 35. 



coccineus, 7. 



confertus, 24. 



cordifolius, 3. 



crassifolius, 1. 



cristaivji, 36. 



cyananthus, 15. 



cyanthus, 15. 



Davidsonii, 2. 



deustus, 33. 



diffusus, 41. 



Digitalis, 30. 



Murray anus, 20. 

 Newberryi, 1. 

 nitidus, 21. 

 ovatus, 37. 

 Palmeri, 31. 

 procerus, 24. 

 pubescent, 38. 

 pulchellus, 26. 

 puniceus, 17. 

 Kichardsonii, 42. 

 Robinsonii, 1. 

 Roezlii, 45. 

 roseus, 26. 

 rotundifolius, 25. 

 Scouleri, 1. 

 secundiflorus, 23. 

 Smallii, 30. 

 speciosus, 15. 

 spectabili?, 34. 

 staticifolius, 39. 

 ternatus, 4. 

 Torreyi, 7. 

 triflorus, 11. 

 tubiflorus, 29. 

 venustus, 40. 

 Wrightii, 18. 



2859. Pentstemon Menziesii var. Newberryi. 

 By many authors considered to be a distinct 

 species, and then known as P. Newberryi. 



(XhO 



gracilis, 28. 



grandiflorus, 19. 



Hartwegii, 12. 



heterophyllus, 47. 



hirsutus, 38. 



humilis, 27. 



isophyllus, 10. 



Jaffrayanus, 46. 



labrosus, 8. 



ketus, 44. 



kevigatus, 30. 



Lemmonii, 6. 



Lobbii, 5. 



Mackayanus, 38. 



Menziesii, 1. 



miniatus, 9. 



A. Cells of anthers de- 

 hiscent for nearly 

 or quite their whole 

 length, united or 

 connivent at the 

 apex and soon 

 spreading from 

 each other. (Nos. 

 1-38.) Nos. 4, 10, 

 16 are in doubt as 

 to position in key. 



Anthers covered with 



long wool. 



1. Menziesii, Hook. Woody at 

 base, 1 ft. or less high: Ivs. thick, 

 obovate to oblong, serrate or entire, 

 mostly glabrous, the lower ones 

 short-stalked: cluster a raceme, 

 pubescent; fls. 1 in. or more long, 

 violet-blue to purple, usually 1 on 

 each pedicel, the upper lip 2-cleft 

 and the lower 2-cleft. Wash., 

 north. G.M. 45:100. 



Var. Newbenyi, Gray (var. 

 Robinsonii, Mast.). Fig. 2859 

 (adapted from Pacific R. R. Re- 

 port). Fls. pink or rose-purple: 

 Ivs. oval or ovate-oblong, serru- 

 late. Calif, to Wash. G.C. 1872: 

 969. Kept specifically distinct by 

 recent authors as P. Newberryi. 



Var. Scouleri, Gray (P. Scou- 

 leri, Douglas). Fls. violet-purple: 

 Ivs. lanceolate to linear-lanceolate, 

 sparsely serrulate. Wyo. to Ore., 

 north. B.R. 1277. B.M. 6834. 

 G.C. III. 7, p. 204. Gn. 52, p. 42; 

 70, p. 250. G. 36:23; 37:408 

 Kept specifically distinct by some 

 as P. fruticdsus, Greene (Gerdrdia 

 fruticosa, Pursh). P. fruticdsus 

 var. crassifolius, Kraut. (P. crassifdlius, Lindl. P. 

 Douglasii, Hook.). Fls. lilac-purple, pink at base: Ivs. 

 oblong or obovate-lanceolate, entire. Ore., north. B.R. 

 24:16. 



2. Davidsonii, Greene. An alpine dwarf, differing 

 from P. Menziesii in having its tough and almost her- 

 baceous branching sts. underground except the very 

 short and erect flowering branches, and obovate and 

 oval obtuse or acutish entire veinless Ivs.: proper st. 

 mainly subterranean and horizontal, rooting at joints; 

 free branches 1-2 in. high, the fls. usually exceeding in 

 size all the remainder of the plant above ground : corolla 



