Eriogoned.] CXXXIV. POLTGONACE^. 93 



aristatis. Flores in involucro oo, pedicellati at subinclusi. Perianthium 6-fid\im, lobis 

 sub^qualibus. Stamina 9, basi perianthii affixa. Ovariiim ovoideum v. oblongnm, 

 obscure 3-quetrum ; styli 3, breves, apice capitato-stigmatosi. Nux coiupressa. Einbryo 

 exccntricus, incurvus, cotyledonibns latis, radicula longa accuinbenti-ascendente.— Herbse 

 annnte, humiles. Folia radicalia rosulata, lineari-spathulata. Rami floriferi e coUo 

 erecti, repetite dichotomi, demum interdum valde accreti et undi(iue intricato-ramosis- 

 simi. Bractere ad dichotomias 3, nunc parvse distinctseque, nunc in unam latam perfo- 

 liatam aristato-3-lobam coalite. Involucra ad dichotomias solitaria, nunc minima longe 

 pedicellata, nunc inter bracteolas sessilia v. subsessilia. 



Species 5, Californics, quarum una etiam in Chili obvia. S. Wats. Bot, Calif, ii. 32 incd,, ei Bot. 

 40 Parall t. 33, 34. Micrs in Trails. Linn. Soc. xxi. 144, t. 17. 



3. Centroste^la, A. Gray in Torr. Bot Parke Exped. 10, t. 8. — Involucrum tubulosum 

 V. infundibuliforme, apice 3-6-dentatum v. lobatum, dentibus rectis s^epius aristatis, extus 

 basin versus calcaribus totidem acutis aristatisve divaricatis instructum. Flores in 

 involucro 2-3 (rarius solitarii 0, pedicellati at inclusi v. vix exserti. Periantbiiim 6- 

 partitum, segraentis angustis suboequalibus. Stamina 9, baai perianthii affixa. Ovarium 

 3-quetrum; styli 3, filiformes, apice capitato-stigmatosi. Nux triquetra. Embryo ex- 

 centricus, incurvus, cotyledonibus latis, radicula elongata accumbenti-ascendente.— Herbm 

 annua), pusilhti, glabrae v. vix puberulse nee lanatae. Folia radicalia rosulata, linean- 

 spathulata. Rami floriferi e collo erecti, repetite dichotomi. Bracteie sub dichotomiis 

 3-partitte v. S-Mse. Involucra ad dichotomias solitaria v. pauca, ad apices ramulorum 

 soepe plura subcapitata. Bracteohe intra involucrum 0. 



Species 2, CalifornicsD, Torr. ct Gr. in Proc. Amcr. Acad. viii. 192. 



Genus quasi medium tenet inter Eriogomtm et ChorizaHthe7n, a S. Wats, in Ppoc. Amer. Acad, 

 xii. 269 huic adjunctum. In CUrizantJic tamen involucra constinter 1-flora et calcaria a S. "Watsomo 

 in C. commissurali e Chile observata rarisbima videntur, nam in specimine nostro desunt nee a 

 G. Gayo memorantur. 



4. Chorizantne, B.. Brr, Benth. in Trmis. Linn. Soc. xvii. 416, t. 19.— Involucrum 

 tubulosum v. infundibulifonne, apice 2-6-dentatum, dentibus acutis aristatisve divaricatis 

 V. riU-ius erectis basi interdum scarioso-dilatatis. Flos in involucro unicus, sessilis 

 v. podicellatus, inclusus v. vix exsei-tus. Perianthium 0-fidura v. 6-partitum, segnieutis 

 siepius c-equalibus. Stamina 0, rarius 3-C, basi v. ad fauccm perianthii affixa. Ova- 

 rium ovoideimi v. oblongum; styli 3, filiformes, apice capitato-stigmatosL Nux 3-gona. 

 Embryo nunc axilis rectus cotyledonibus angustis, nunc excentriciis incurvus cotyle- 

 donibus latis, radicula elongata accumbenti-ascendente.— Herbje suffruticesve glabrie 

 pubescentes v. sericeo-villosje, nee lanatse. Folia saiplus anguata, radicalia rosulata, in 

 parte inferiore caulis opposita v. verticillata. Rami floriferi erecti dichotomi v. primarii 

 rarius umbellati. Bracte^e ad dichotomias 3, srepe in unam 3-fidam connate, v. sub 

 mnbella plures. Involucra ad dichotomias solitaria v. pauca, summa tamen v. interdum 

 inflorescentia tota in cymam densam capitulumve tcrminale conferta, singula basi ssepe 

 demum indurata, calcarata tamen adhuc non vidimus. 



Species ad 30, quarum 8 Chilenses perennes v. suffrutescentes cum una annua, Benth. in DC. Prod. 

 xiv. 24; c^ter* omnes annu» CalifornicEe. Torr. et Gray in Proc. Amer. Acad. viii. 192, ubi in 



seetiones 3 boquentes distribuuntur. . .. ■ 



1. Euchorisanihc. Involucrum 6-dentatum, 6-e03tatum. Stamina juxta basin perianthii aifixa. 

 Hue pertinent species Chilenses cum plerisque Califomicis. Chohisanthe, Benth. I.e., Torr. 



Bot. WUlianison Exped. t. 8. 



2. Mueronea. Involucrum 2-4-dentatum. Stamina juxta basin perianthii affixa. Bractc^ad 



dichotomias in unam latam 3-fidam interdum perfoliatam connatie. Species 2, CaUfomicae. 

 MuCRONEA, Benth. in Trans. Linn. Soc. xvii. 419, t. 20. 



3. Acanthogonum. Involucrum 3-5-dentatum, transverse corrugatum. Stamina fauci perianthu 

 breyiter 6-lobi affixa. Species 2, Californicae. 5. Wats. Bot. 40 Parall t. 34. Acanthogonum, 

 T<yrr. Bot. Whipple Exped. 132 (76). 



