Trap structure of the carnivorous plant Genlisea (Lentibulariaceae) Autor(en): Reut, Markus S. Objekttyp: Article Zeitschrift: Botanica Helvetica Band (Jahr): 103 (1993) Heft 1 PDF erstellt am: 05.03.2016 Persistenter Link: http://dx.doi.org/10.5169/seals-71331 Nutzungsbedingungen Mit dem Zugriff auf den vorliegenden Inhalt gelten die Nutzungsbedingungen als akzeptiert. Die ETH-Bibliothek ist Anbieterin der digitalisierten Zeitschriften. Sie besitzt keine Urheberrechte an den Inhalten der Zeitschriften. Die Rechte liegen in der Regel bei den Herausgebern. Die angebotenen Dokumente stehen für nicht-kommerzielle Zwecke in Lehre und Forschung sowie für die private Nutzung frei zur Verfügung. Einzelne Dateien oder Ausdrucke aus diesem Angebot können zusammen mit diesen Nutzungshinweisen und unter deren Einhaltung weitergegeben werden. Das Veröffentlichen von Bildern in Print- und Online-Publikationen ist nur mit vorheriger Genehmigung der Rechteinhaber erlaubt. 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Trap structure ofthe carnivorous plant Genlisea (Lentibulariaceae). Bot. Helv. 103: 101-111. The developmental morphology of the trap of five Genlisea species (G. africana, G. hispidula, G. pygmaea, G. repens and G. subglabra) from South America and Africa is described. Studies are based on living and preserved material using scanning electron microscopy. The traps show interspeeifie differences in types of detentive hairs and the occurrence of stomata. Highly decomposed organisms were found in the traps, especially in the bulb and proximal neck. Genlisea and Utricularia (Lentibulariaceae) show similar¬ ities in early development of the trap and anatomy of external glands. Key words: carnivory, detentive hairs, developmental morphology, digestion, Gen¬ lisea, Lentibulariaceae, stomata, trap, Utricularia. 1. Introduction Genlisea A. Saint-Hilaire belongs to Lentibulariaceae (Order Scrophulariales) (Takhtajan 1987). Most literature on Genlisea is cited in Taylor (1991). The genus is closely related to Utricularia of the same family. The flower of Genlisea has a five-parted calyx, while Utricularia shows a two-parted calyx (Taylor 1991). Genlisea is divided into two sections, depending on the type of capsule dehiscence. Section Genlisea has circumscissile dehiscence, while Tayloria has longitudinal (Fromm-Trinta 1979). The five species (G. africana Oliver, G. hispidula Stapf, G. pygmaea A. Saint-Hilaire, G. repens Benjamin and G. subglabra Stapf), examined in this paper, belong to section Genlisea, which occurs in both Africa and South America. Eight Genlisea species are known from tropical and South Africa and 11 from Central and South America (Taylor 1991). Some species pairs are difficult to identify on floral characters, e.g., G. repens and G. pygmaea, and G. hispidula and G. subglabra (Taylor 1991). Trap morphology was considered to be of limited use in the Classification of Genlisea (Taylor 1991). One aspect of this study was to reexamine the systematic significance of trap morphology. Genlisea occurs in wet meadows, sandy riverbanks and marshy grasslands and can seasonally be submerged (Cook 1990, Taylor 1991). These habitats are well known for the development of the carnivory Syndrome in plants (Heslop-Harrison 1978). 101 !02 m. S. Reut Most Genlisea species possess a rosette of green leaves on a short rhizome. Only G. repens has a creeping elongated rhizome. Besides the foliage leaves, the rhizome bears whitish subterranean or submerged organs, which were considered by Darwin (1876) to trap for catching small invertebrates. Goebel (1891: Fig. 5, Taf. XV) found animals and algae in the bulb ofthe Genlisea trap. Although carnivory sensu stricto (i.e;, attracting, capture and digestion: see Juniper et al. 1989) in Genlisea has not been conclusively demonstrated, the term trap is used for convenience to describe this structure. The trap is the only organ of Genlisea, which has positively geotropic growth. Genlisea lacks a typical root system. The trap seems to have both root and leaf characteristics, so it was therefore called "Wurzelblatt" by Schmucker und Linnemann (1959). Previous morphological and histological works on the flower and trap of Genlisea spp. were provided by Warming (1874: G. aurea A. Saint-Hilaire, syn. G. ornata Martius), Goebel (1891: G. aurea; 1893: G. violacea A. Saint-Hilaire), Lloyd (1942: Genlisea spp. including G. filiformis Benjamin, G. repens) and Fromm-Trinta (1979: G. aurea, G. filiformis, G. pygmaea, G. repens and G. violacea). These studies were restricted to South American species. Juniper etal. (1989, p. 125) stated that early studies were primarily based on dried and fixed material and "therefore any explanation of how the trap works is purely speculative". The present study uses both living and preserved plant material of South American and African species. It aims to provide an understanding of the trap function, focussing on trap histology and morphology, using scanning electron micros¬ be a copy. 2. Material and methods The following material of Genlisea has been studied (N fixed material from natural site, ZH eultivated plants grown at the Botanical Garden of Zürich University, Switzerland). Species from South America Genlisea pygmaea A. Saint-Hilaire N: Trinidad, Baker & Simmonds et al. 17. Nov. 1951 No. 6 (spirit collection Kew) ZH: young plants provided by L. Bütschi s.n. (origin of seeds: Auyan-Tepui, Estado Bolivar, Venezuela) Genlisea repens Benjamin N: Auyan-Tepui, Estado Bolivar (Venezuela), L. Bütschi s.n. ZH: seeds from Auyan-Tepui, Estado Bolivar (Venezuela), L. Bütschi s.n. Species from tropical and South Africa Genlisea africana Oliver N: Liberia: Baldwin 13003 (spirit collection Kew) Genlisea hispidula Stapf ZH: plants provided by R. Fürst s.n., source unknown ZH: plants provided by L. Bütschi s.n., source unknown Genlisea subglabra Stapf N: Tanganyika: Redhead & Taylor 8009 (spirit collection Kew) In 1988, Lorenz Bütschi (present address: Horticulture, Qu. les Vignaux, B.P. 22, F-83520 Roquebrune sur Argens, France) collected living material of G. repens and G. pygmaea on the Auyan-Tepui (Venezuela). Cultures of these two closely related species at the Botanical Garden of Zürich are relatively large. Botanica Helvetica 103/1, 1993 103 Most fixed material was preserved in a mixture of ethanol and glycerine (Kew mixture). One % glycerine in 70% ethanol Solution was fixative for the preparation of G. repens (N, ZH) and G. pygmaea (ZH). A Hitachi S-4000 field emission scanning electron microscope (SEM) was used for morphological examinations on Genlisea spp. 3. Results: Anatomy and development The trap of the Genlisea trap of Genlisea is a complex structure which consists of a footstalk PI and an utricle (Fig. 1). The utricle has a hollow bulb P2, a tube (neck) P3, and two twisted arms P5 (Fig. 1). There are up to 20 twists in each arm. The arms are tube-like but have a longitudinal slit. The prey enters the trap through the mouth (Lloyd 1942) of the branching zone P4, and also through the slits of the arms. General histology of the trap varies and is well described by Lloyd (1942). The footstalk consists of an epidermis and aerenehyma. The only vascular Strand divides at the distal end of the footstalk into a dorsal and ventral vascular Strand before entering the bulb. These Strands divide once more at the branching zone. Therefore, each arm contains vascular tissue of dorsal and ventral origin. The utricle of the Genlisea trap consists of two epidermal layers, sometimes divided by parenchyma. 3.1. The inner epidermis of the trap The inner epidermis of the Genlisea trap contains hairs, glands, supporting cells and occasionally stomata. The supporting cells are of two types underlying basal cells of hairs and pedestal cells of glands. Glands ofthe inner epidermis generally possess multicellular heads which are one cell-layer thick (Fig. la-i). 3.1.1. Detentive hairs "Detentive hairs" or "bristles" (Lloyd 1942) occur on the inside ofthe neck and arms ofthe trap. These hairs are oriented towards the bulb and are thought to have a detaining role. In the arms, there are rows of these hairs, while in the neck they form about 40-60 complete funnels. Detentive hairs seem to be extensions of long narrow supporting cells (Fig. 2), which are part of the inner epidermis of the neck and arms. The detentive hairs are 2-3-celled (Fromm-Trinta 1979). They consist of a basal cell, a terminal cell and, occasionally, a middle cell (Fig. 4). In the species examined, only G. africana has 3-celled detentive hairs, which are restricted to the proximal neck. The zone between two rows of detentive hairs of the same type is referred to as a "segment". The appearence of segments is loosely defined by constrictions ofthe external wall of the neck. Detentive hairs in South American Genlisea spp. were studied in detail by FrommTrinta (1979). She demonstrated that the shape of terminal cells of these detentive hairs is quite variable. The types of terminal cells in G. repens and G. pygmaea were described by Fromm-Trinta (1979) and studied using SEM in this paper. In the African species (G. africana, G. hispidula and G. subglabra), different hair types occur from those present in the South American taxa. The hair types differ in the shape of both the terminal and basal cell (Tab. 1). Hair types, not known from South American species (see FrommTrinta 1979), are basal cells with an obvious longitudinal furrow, terminal cells with globose apex, and pusticulate basal cells (Figs. lj-1, n, 3, 4, 5). In South American and 104 M. S. Reut rhizome T PI 1 -—nr P2 i •$\ f 9)/ /vi 7$ P3 f:. ¦"l\i ':t' 1 P4 ^f ¦ .«;."; ¦*' 'Vi '**•£' ••'i.M .'Nv-1 ,'•'•/'¦ '^: vi yy .'•'S- -'¦'j,\ ¦tfj 1 1 '¦im v*\ •VjJJ '**.l '•«V*|';iV;l ¦'¦fl '.'41 \3 *> fT\ P5 f}*fl ¦ M5 1 ;«f .'.;•> (L m n 1. Trap of Genlisea: PI -P5. Trap of Genlisea: PI. Footstalk. P2. Hollow bulb. P3. Neck (tube). P4. Branching zone. P5. Arms. a-m. Glands and hairs of inner epidermis of bulb and neck: a-b. Glands in the bulb: a. G. pygmaea: 4-celled gland. b. G. hispidula: 8-celled gland. c-e: Slightly different shapes of 4-celled glands ofthe proximal neck: c. G. hispidula. d. G. repens. e. G. subglabra. 2-celled glands ofthe distal neck: f. G. hispidula. g. G. subglabra. h. G. africana. i. G. repens. j -m. Detentive hairs ofthe proximal and/or distal neck (definition ofthe types see Tab. 1): j. G. hispidula and G. subglabra (type LA), k. G. subglabra (type LG). 1. G. africana (type PK), m. G. repens (type SC), n. G. hispidula (type PB). P2 is 2 mm in G. repens. Scale bar for a-n is 10 um. Fig. f-i. African species, a slightly developed longitudinal furrow in the basal cell is occasionally present in the smooth cylindrical type (Fig. 1 m). Tab. 1 shows that different hair types may occur in the various parts of the trap. In the arms of G. africana, the middle neck of G. hispidula, and the distal neck and arms of G. subglabra, two distinet hair types are present within each row of detentive hairs (Tab. 1, Fig. 3). The detentive hairs with pusticulate basal cell and awl-shaped terminal Botanica Helvetica 103/1, 1993 Tab. 1. Detentive hair types G. of Genlisea africana arm p m d SA2 PA3 PK4 type arm m PK4 d PB4 SK3 PB4 PB4 SA3 SAj neck arm p m ÖV-^T Ü3 v_- d T — i sc2. -3 SC3_4 SAj G. subglabra neck type neck p G. repens hair G. pygmaea G. hispidula neck hair 105 arm p m d Ov^2 ävi SC4 neck p arm m d SC3_ 4 LA2_4 i-,J\.2- 4 LB2 4 LB2- 3 LG2 -3 LG2. -3 SAt Part of neck: p, proximal; m, middle; d, distal (including branching zone). Detentive hair type: Basal/middle cell (Ist letter): L, with deep longitudinal furrow and smooth sur¬ face. P, + cylindrical, with pusticulate structure. S, + cylindrical, with smooth surface. Terminal cell (2nd letter): A, awl-shaped; B, blunt; C, cuspidate; G, distal part globose; K, club-shaped. Index numbers stand for different classes of size or lengths: 1, 40-60 (im; 2, 61-120 |im; 3, 121-150 um; 4, 151-230 um. cell in G. hispidula and the detentive hairs with longitudinal furrowed basal cell and blunt terminal cell in G. subglabra may be viewed as intermediates between two hair types (Tab. 1, Fig. 3). In G. repens, up to 3 rows of short hairs of one type occur along the margins ofthe arm slits (Tab. 1). Normally, G. pygmaea has no short hairs on the margins (Fromm-Trinta 1979: Fig. 13A, Reut pers. obs.). One specimen of G. pygmaea (ZH), however, showed 3-4, closely spaced rows of short hairs ofthe same type (Tab. 1). In the arms of G. hispidula, one single row of short hairs is present along the margins of the slit, and 2 rows of detentive hairs within a segment. In this species, these rows are closely spaced together, and each row is characterized by a distinet hair type (Tab. 1). This was also shown in G. aurea by Fromm-Trinta (1979: Figs. 12B + C). 3.1.2. Other structures of the inner epidermis In each segment, up to 3 rows of glands occur. These glands are borne on supporting cells with sinuous margins, and consist of a short pedestal cell and a multicellular head (Figs 3, 6). In the arms, the branching zone, and the distal and middle part of the neck, the glandulär head is composed of 2 terminal cells (Fig. 6). In the proximal neck, the head consists of 2-4 cells (Fig. 7), rarely 8 cells as occasionally in G. pygmaea. The 2-celled glandulär head is ventro-laterally attached to the inner epidermis by the pedestal cell (Fig. 6), while the 4-celled head is centrally fixed to the inner epidermis by the pedestal cell. The shapes of 2-4-celled heads are quite variable within the species examined (Fig. 1 c-i). These shapes seem to be of little value for the identification of species. 106 M. S. Reut -''£.-«' m irymmm *: iL % ¦li;:!!!!::;;;! '¦:::!!!:!!::!!!!!"!!;. LiLhi. r/-z. y. s*. V i ^<*, L jiLflLLL fflLr Afk'¦¦¦¦" r ¦ 1 r ¦ '$*Lm; '-i,- ¦t.^-.HSmgp v, ; ¦rr ¦¦¦ m ¦Htt Ar, '''" mm A AA rAflM, ';Afliflflfl: r-r:>fl. ¦¦¦¦¦iA. '*->¦ fl \ A .Ar.fl r^«SS&i* -rrflr:-¦ ¦. i-A L 6 \ V ./'?% t: Figs. 2-7. Genlisea spp.: Detentive hairs and glands of trap: 2. Proximal neck of G. repens showing "supporting cells" (s) of detentive hairs (d), 4-celled glands (f) and 2-celled glands (t) (168 x). 3. Branching zone of G. subglabra showing detentive hairs terminal cells of globose and blunt (arrow) type (233 x). 4. Middle neck of G. subglabra with awl-shaped terminal cell and longitudinal furrow (arrow) of basal cell of detentive hairs (654 x). 5. Distal neck of G. africana showing pusticulate structure (arrow) of detentive hairs (747 x). 6. Glandulär trichome in the arm of G. repens with pedestal cell (arrow) and 2-celled head (h) (1867 x). 7. Proximal neck of G. hispidula with 2- and 4-celled glands and awl-shaped terminal cells of detentive hairs (467 x). 107 Botanica Helvetica 103/1, 1993 o .1 -A' .:.: *^B 11 10 t*!':1 mm 9fl\ LI,: flflr'flflfl., t&- i : flfl, : :.,. «" 111 fli 3 * LirK/f M mJLiviiL Lk:.,;LA: ¦ AflA ¦rrirr Sr :';: IJ 13 I Figs. 8-13. Genlisea spp.: Figs 8-9. Details of the trap arm: 8. Stoma of inner epidermis of G. twisted arm repens trap surrounded by cells with sinuous margins (1027 x 9. Portion of helically 10. bulb Bulb: Opened 10-11. of G. africana with bridge (b) and external glands (g) (121 x). Figs inner the scattered 8-celled few on and glands a of G. repens showing ridge (arrow). Many 4-celled bulb surface (37 x). 11. Detail of Fig. 10 showing ridge with 4-celled glands (233 x). 12. 4-celled glands on inner wall of bulb of G. subglabra (420 x). 13. 8-celled gland on inner wall of bulb of G. hispidula (840 x) 108 M.S. Reut Goebel (1891) observed stomata on the inner epidermis ofthe distal neck and arms of G. aurea. These internal stomata were found in all species studied, except G. subglabra. In G. repens and G. pygmaea, the stomatal number varies in different parts of the trap. In the neck, up to 2 stomata occur per segment, while in the arms no more than 4 stomata are present in each segment. In G. hispidula, normally a single Stoma occurs in each segment of the arms. The stomata of the inner epidermis of these three species are anomocytic (see Dilcher 1974) and surrounded by 5 epidermal cells (Fig. 8). The guard cells are raised above the epidermal cells. The long axis of guard cells is parallel to the long axis of the trap. In the arms and branching zone of the Genlisea trap, unusually shaped trichomes occur at regulär intervals of about 0.25 mm. Lloyd (1942) called them "distance pieces" or "articulating hairs", because they articulate and support the two margins of the arm slit (Fig. 9), and seem to avoid its collapse. The basal and middle cell of these trichomes separate the margins of the arm slit. They were referred to by Juniper et al. (1989) as a "bridge" or by Lloyd (1942) as a "prop-cell". The basal and middle cell are much enlarged, whilst the apical cell is reduced and button-like in appearance (Lloyd 1942). In general, hairs, glands and supporting cells ofthe distal neck continue into the arms. Glands and supporting cells of detentive hairs ofthe arms are usually smaller than those of the distal neck. The inner epidermis of the bulb differs from that of the more distal parts of the Genlisea trap. The inner surface of the bulb contains isodiametric, straight-walled cells. Many glands occur irregularly on the inside of the bulb (Fig. 10). These glands consist of a short pedestal cell, supporting 4 to 8 terminal cells (Figs. 12, 13); the 4-celled glands are much more frequent. Many crowded, 4-celled glands are present on the proximal inner side ofthe bulb and extend ventrally and dorsally on either side above the vascular bundles. In the species examined, these crowded glands are attached to an internal ridge (Figs. 10, 11), except in G. subglabra. Whilst the multicellular heads ofthe glands in the neck are flattened, the terminal cells of the glands in the bulb are more spherical. 3.2. The outer epidermis Many button-like trichomes (glands) are present irregularly on the outer epidermis of the trap. These trichomes are similar in appearance to the external glands of the Utricularia bladder (Juniper et al. 1989). In both genera, they consist of a pedestal cell and a head. The pedestal cell is supported by a basal cell, which is normally surrounded by 4, straight-walled, hexagonal epidermal cells (Fig. 14). Differences between Genlisea and Utricularia exist in the number of head cells of the external glands. Single-celled heads occur in G. repens, G. pygmaea, G. africana, and G. hispidula (Fig. 14), and were recorded in U. dichotoma by Richter (1990: p. 27, Fig. 3 b). Two-celled heads of external glands are present on the bulb of G. subglabra (Fig. 15), and were found in U. minor by Kristen (1974). Stomata are absent from the external epidermis of the trap of all examined Genlisea species, except G. africana. Stomata of G. africana are anomocytic, and restricted to the outer epidermis ofthe neck. Their guard cells are usually surrounded by 4 epidermal cells and raised relative to them. The long axis of the guard cells are oriented parallel to the long axis of the trap. 109 Botanica Helvetica 103/1, 1993 AflflflrAr¦; »AAlrAflm SJSli ¦ if J.:"f * '"*.;, \ flifli. Jimm rflfl": r r ,r. : : ::.«:;,. fl: .JL.¦ fl' --flj^t•• ¦ 11ffrrü ;*»* »ji1 ¦¦'' ¦ ¦ : m W 15 ---2*9 ;j;*s», irr: ¦ 'Lflsi;. ':.fflMM¥fli:w>iffl\ 'WhSiW¥;fl,M^Xflfl^ 16 M * tSy'L :*' ?}. LL c s Figs. 14-19. Genlisea spp.: 14-15. Glands on outer epidermis of trap. 14. Single-celled glands of G. repens (840 x). 15. Two-celled glands on G. subglabra bulb (934 x). Figs. 16-19. Trap develop¬ ment of G. repens: 16. Young bulb with primordial neck. Arrow points to opening of tubulär neck (140 x). 17. Neck apex with ventral mouth (560 x). 18. Initiation of arms due to transversal extension of mouth region (373 x). 19. Young folded arm with coiled tip (280 x). 110 M.S. Reut 3.3. Trap development Development ofthe Genlisea trap was described by Goebel (1891), Troll (1939), Lloyd (1942), and recently reviewed by Juniper etal. (1989). Development of the trap initially involves formation of a cylindrical primordium from the rhizome. This stalk grows by an apical meristem. The ventral side of this apical tip then widens by invagination to form a gullet, which enlarges into a hollow structure (Lloyd 1942) (Fig. 16). The next stage in Genlisea trap development is a lateral extension of the apex on both sides, which causes the opening to become a mouth (slit) (Fig. 17). The lateral sides of the mouth bend proximally because cell divisions occur more rapidly on the dorsal side than the ventral (Fig. 18) (Goebel 1891). Helically twisted arms develop on both sides of the mouth. One arm twists clockwise and the other counter clockwise. The tips of the arms are initially coiled (Fig. 19), but straighten by the end of arm development. The inner and outer epidermis of the trap show differentiated glands and hairs early in development. 4. Discussion It is sometimes difficult to identify species of Genlisea using only floral characters According to Taylor (1991), there seems to be little floral variability within the Fromm-Trinta (1979) and my results demonstrate that the anatomy ofthe detentivegenus. hairs in the Genlisea trap shows interspeeifie variability. African species, examined in the present study, show hair types which are not present in the South American species described by Fromm-Trinta (1979). The occurrence and number of internal or external stomata of the Genlisea trap seems to be characteristic at the level of species. FrommTrinta (1979) noted that on the inside of the bulb, only 4-celled glands occur in G. pygmaea, and 4-6-celled glands in G. repens. In the present study, 4-8-celled glands were observed on the inner wall of the bulb of both species. The early development of the trap (especially its stalk) is characterized by prolonged apical growth, which is typical for roots in most flowering plants (Goebel 1891, 1913). The morphology ofthe Genlisea trap at the primordial stage is similar to young stolons of several Utricularia species (see Brugger and Rutishauser 1989). The mouth develop¬ ment of the Genlisea trap (Fig. 17) resembles the early development of the Utricularia bladder (see Goebel 1891; Lang 1901: Fig. 8; Brugger und Rutishauser 1989: Fig. 38). It is not clearly known, why small aquatic organisms enter the Genlisea trap (Taylor 1991). Perhaps looking for shelter, animals creep into the slits ofthe arms. It is unclear, whether the Genlisea trap funetions by active and/or passive processes. Passive capture of prey is possible as once inside the trap, the prey has little chance to turn back, because the detentive hairs block the exit. There are many rows and funnels of hairs in the mature trap. Each funnel extends into the next. Therefore, the whole Genlisea trap funetions as a series of traps. This function of the Genlisea trap was alluded to by Darwin (1876) as an "eel trap" and by Heslop-Harrison (1975) as a "lobster pot". The only possible movement for the prey is unidirectional and leads directly into the bulb of the trap. Highly disintegrated organisms are found especially in the bulb and proximal neck ofthe Genlisea trap (Lloyd 1942, Reut pers. obs.). Therefore, the glands in these parts ofthe trap possibly play digestive and absorptive roles. It is also possible that a suetion mechanism exists which results in an active movement of water, soil particles and organisms into the trap. Joel (unpublished obs.) found mud Botanica Helvetica 103/1, 1993 Ul particles amongst animals in the bulb and neck of Genlisea traps (Juniper et al. 1989). This would suggest that either a water current or an active process of suction is respon¬ sible for the movement of these particles and organisms into the trap (Juniper et al. 1989). Alternatively, animals could have transported these mud particles into the neck and bulb. I am grateful to Dr R. Rutishauser and Mr C. Wagner for advice and critical comments on the manuscript, Dr C. D. K. Cook and Mr A. Rozefelds for help with English, Mr L. Bütschi for providing living plants, Dr P. Taylor (Kew) for preserved material, and Mr U. Jauch for technical assistance with SEM. References Brugger J. und Rutishauser R. 1989. Bau und Entwicklung landbewohnender Utricularia-Arten. Bot. Helv. 99: 91-146. Cook C. D. K. 1990. Aquatic plant book. The Hague: SPB Academie Publ. Darwin C. R. 1876. Insektenfressende Pflanzen. Genlisea: 400-405. Stuttgart: E. Schweizerbart'sche Verlagshandlung. Dilcher D. L. 1974. Approaches to the identification of angiosperm leaf remains. Bot. Rev. 40: 1-157. Fromm-Trinta E. 1979. Tayloria Fromm-Trinta: Revisao das especies do genero Genlisea St.-Hil. (Lentibulariaceae) das regiöes sudeste e sul do Brasil. Rodrig. 31(49): 17-139, figs. 1-35. Goebel K. 1891. Genlisea. Lentibulariaceae. Pflanzenbiologische Schilderungen 2: 121-127, Tab. 15-16. Marburg: El wert. Goebel K. 1913. Organographie der Pflanzen I: 1-4. Jena: Gustav Fischer. Heslop-Harrison Y 1975. Enzyme release in carnivorous plants. In: Lysosomes in Biology and Pathology 4. Dingle J. T. and Dean R. T. (eds.): 525-578. Amsterdam: North Holland Publ. Comp. Heslop-Harrison Y 1978. Carnivorous Plants. Sei. Amer. 1978: 104-115. Juniper B. E., Robins R. J. and Joel D. M. 1989. The Carnivorous Plants. London: Academie Press. Kristen U. 1974. Feinstruktur und Entwicklung der äußeren Fangblasendrüsen von Utricularia minor L. Cytobiologie 9: 321-330. Lang F. X. 1901. Untersuchungen über Morphologie, Anatomie und Samenentwicklung von Polypompholyx und Byblis gigantea. Flora 88: 149-206. Lloyd F. E. 1942. Genlisea. The Carnivorous Plants: 90-94, Tab. 11-12. Waltham, Mass.: Chronica Botanica Comp. Richter U. 1990. Die Fangblasen von Utricularia cf. praelonga St. Hil. und Utricularia dichotoma Lab. - eine rasterelektronenmikroskopische Untersuchung. Flora 184: 21-30. Schmucker Th. und Linnemann G. 1959. Carnivorie. In: Handbuch der Pflanzenphysiologie. Ruh¬ land W. (ed.). 11, Heterotrophy: 251-253. Berlin: Springer. Takhtajan A. 1987. Lentibulariaceae. Systema Magnoliophytorum: 252. Leningrad: Nauka. Taylor P. 1991. The genus Genlisea. Carniv. Plant Newsl. 20: 20-35. Troll W. 1939. Vergleichende Morphologie der höheren Pflanzen. Band 1/2: 1864-1866. Berlin: Gebrüder Borntraeger. Warming E. 1874. Bidrag til Kundskaben om Lentibulariaceae. Vid. Medd. Nat. For. Kjobenhavn 1874: 33-45