110 



KEY TO THE FAMILIES AND GENERA 



B, FT. a drupe; endocarp hard, thick or thin: 



infl. axillary, rarely terminal 10. Olea. 



Ba. Fr. a berry, hardly drupaceous; endocarp 

 membranous or tliinly coriaceous: pani- 

 cles terminal 11. Ligustrun 



122. LOGANIACE.ffi. 



A. Style 2-fid, branches linear, 2-fid 1. Gelsemium. 



AA. Style simple. 



B. Corolla-lobes valvate. 



c. Fr. a circumscissile caps 2. Spigelia. 



cc. Fr. an indehiscent drupe or berry 3. Strychnos. 



BB. Corolla-lobes imbricate. 



c. Anthers exserted 4. Chilianthus. 



cc. Anthers included 5. Buddleia. 



The genus Logania may afford cultivated plants now and then. 



123. GENTIANACE.E. 



A. Lvs. alternate or radical. 



B. Fr. indehiscent 1. Nymphoida. 



BB. Fr. dehiscent. 



c. Caps, usually 4-valved at apex 2. Villarsia. 



cc. Caps, irregularly sub-2-valved at apex 3. Menyanthes. 



AA. Lvs. opposite. 



B. Ovary perfectly 2-celled; placentie solitary 

 in each cell, often thick, adnate to septum; 



liberated by dehiscence of caps 4. Exacitm. 



BB. Ovary 1-celled; placentiferous margins of 

 carpels mo_re or less intruded within or 

 even touching but not connate in the mid- 

 dle of the cell, spuriously 2-celled. 

 C. Style often deciduous; anthers usually 

 erect. 



D. Anthers spirally twisted finally 5. Erythrxa. 



DD. Anthers finally recurved at apex 6. Sabbatia. 



cc. Style usually persistent; anthers versa- 

 tile, finally recurved 7. Lisianthus. 



BBB. Ovary 1-celled; margins of carpels rarely 

 intruded; ovules and seeds affixed at 

 each side of the suture in 1 series or more 

 or less extended over the parietal surface; 

 placentas adnate, very thin. 

 C. Corolla has 1-2 pits at base of each lobe. 



D. Style short or scarcely any 8. Swertia. 



DD. Style subulate 9. Frasera. 



cc. Corolla has no such pits 10. Gentiana. 



The genus Chironia may also be expected in cultivation. 



124. ASCLEPIADACEjE. 



Subfamily 1. PERIPLOCE.ffi. Pollen granular, loosely aggre- 

 gated in 2 masses in each anther-cell. 



Character of subfamily 1. PERIPLOCA TRIBE. 



Subfamily 2. EUASCLEPIADE.ffi. Pollen waxy, the masses 

 solitary in each anther-cell. 



Anthers tipped by a membrane, which is 



inflexed or sometimes erect, and usually 



hyaline, rarely opaque or petal-like; 



pollen-masses suspended, attached in 



pairs (1 in each adjacent cell of different 



anthers) to the corpuscle or gland 2. CYNANCHUM TRIBE. 



Anthers usually tipped by an inflexed or 



suberect membrane, which is hyaline, 



rarely opaque; pollinia solitary in each 



cell, erect or very small 3. MAHSDENIA 



Anthers obtuse at apex, not appendaged [TRIBE. 



or rarely the connective produced ; pol- 

 linia solitary in the cells, erect 4. CEROPEOIA TRIBE. 



Anthers like those of the Ceropegiese or 



more incumbent above the top of the 



stigma or subimmersed: sts. thick and 



fleshy, leafless or with a few lys. at top. . 5. STAPELIA TRIBE. 

 Anthers broad at the top, without ap- 

 pendages or more or less membranace- 



ous on the margins, the cells somewhat 



transversely dehiscent, attac hed 



nearly or quite on the margin of the 



stigma -disk; pollinia horizontal or 



essentially so 6. GONOLOBCS TRIBE. 



1. Periploca Tribe. 



A. Scales of corona distant from staminal tube. 

 B. Corolla-tube short; scales linear or club- 

 shaped 1. Cryptolepis. 



BB. Corolla large, funnel-shaped; scales acumi- 

 nate or 2-fid 2. Cryptotlegia. 



AA. Scales of corona close to stamens. 



B. Corolla-lobes valvate 3. Chlorocodon. 



BB. Corolla-lobes imbricate 4. Periploca. 



Physianthus. 

 Philibertia. 



Oiypetalum. 



Asclepias: 

 Calotropis. 



Podostigma. 



Morrenia. 



Cynanchum. 



Vincetoxi- 



[cum. 



Rothrockia. 



2. Cynanchum Tribe. 



A. The outer or single crown either simple and 

 composed of 5 scales or ring-shaped, adnate 

 to the corolla and not the staminal tube, or 

 rarely adherent to both. 



B. Stigma depressed 5. 



BB. Stigma umbonate or 2-beaked at apex: 

 corona-scales attached at middle (or 



below) of corolla-tube 6. 



BBB. Stigma plane or umbonate; corona annular, 



adnate to corolla 7, 



AA. The crown of 5 scales affixed to base of 

 corolla and staminal tube; caudicles of pol- 

 linia appendaged with an erect fuscous 



tooth g. 



AAA. The crown of 5 scales which are distinct, 

 affixed or adnate to the staminal tube or 

 the back of the anthers. 

 B. Scales concave or hooded with an acute 



ligula inside 9. 



BB. Scales fleshy, narrow, adnate to stamen- 

 tube, but free and recurved at base 10. 



BBB. Scales (5 outer ones) carinate-complicate 

 at base of staminal tube; the 5 scales at 

 the apex of the long staminal tube, short, 

 obtuse, spreading, alternate with anthers. .11. 

 AAAA. The outer or single crown affixed to the 

 staminal tube, ring- or cup-shaped, entire, 

 lobed or parted. 



B. Corona villous inside 12. 



BB. Corona with 5 scales or ligula? inside 13. 



BBB. Corona naked inside 14. 



BBBB. Corona of 5 short processed opposite anthers 

 and 10 ligulffi alternate with anthers in 

 pairs 15. 



3. Marsdenia Tribe. 



A. Corolla-lobes strictly valvate 16. Hoya. 



AA. Corolla-lobes usually overlapping dextrorsely. 

 B. Fls. not pure white, urn- or salver-shaped, 



small or medium-sized 17. Marsdenia. 



BB. Fls. white, salver- or funnel-shaped, large ... 18. Stephanotis. 



4. Ceropegia Tribe. 



Corona double, affixed to staminal tube 19. Ceropegia. 



5. Stapelia Tribe. 



Corona double, outer spreading, inner of 5 scales. 20. Stapelia. 



6. Gonolobus Tribe. 



Crown cup-shaped or annular, entire or lobed .... 21. Gonolobus. 



Additional genera described in Asclepiadaceie are: Caralluma, 

 Duyalia, Echidnopsis, Gomphocarpus, Hoodia, Huernia, Mieho- 

 litzia, Pectinaria, Piaranthus, Raphionacme, Sphaerocodon and 

 Trichocaulon. 



125. APOCYNACE.fi. 



A. Anther-cells not appendaged at base. 

 B. Ovary entire (Carissa Tribe); fls. 5-merous. 



0. Fr. a 2-vaIved caps.: ovary 1-celled 1. Allamamla. 



cc. Fr. a berry, indehiscent: ovary 2-celled; 



cells 1-4-ovuled. 



D. Ovules laterly affixed: cymes ter- 

 minal, few-fid: spines axillary 2. Carissa. 



DD. Ovules erect from base: cymes axillary, 



dense: spines 3. Acokanlhera. 



BB. Ovaries 2 to several; style 1 (Plumeria Tribe), 

 c. Calyx with several glands inside or a ring 

 of hairs. 



D. Carpels 2-ovuled 4. Thecelm. 



DD. Carpels many-ovuled 5. Tabernx- 



cc. Calyx without glands inside. \montana. 



D. Carpels 2-ovuled. 



E. Disk 2-scaled 6. Kopsia. 



EE. Disk cup-shaped or annular 7. Rauwolfia. 



DD. Carpels 0- to many-ovuled. 

 E. Ovules in 2 series. 

 F. Disk 0. 



a. Seeds truncate 8. A msonia. 



Go. Seeds winged 9. Gonioma. 



FF. Disk of 2 scales 10. I'lnni. 



EE. Ovules in many series. 



F. Stamens near base of tube 11. I'lumrria. 



FF. Stamens above middle of tube 12. Alstonia. 



AA. Anther-cells produced at base. (Echitrs 



Tribe.) 



B. The cone of anthers more or less exserted 

 at apex. 



c. Throat of corolla with 5 scales 13. Prestonia. 



cc. Throat without scales 14. Vallaris. 



BB. The anthers included. 



c. Lvs. usually in whorls of 3 15. .Verium. 



